In contemporary Croatian biomedical terminology, a coexistence of Latin terms, terms comprised of international loanwords, and Croatian terms is present. Although there are Croatian equivalents accepted by the profession for many international loanwords, the transparency and recognisability of the loanwords from Greek and Latin in different national languages, their efficiency and great word formation capabilities give them a privileged status in the language of biomedicine. Besides being mostly comprised of words stemming from classical languages, biomedical terminology is now under the strong influence of the English language, which has become the lingua franca of modern science and technology. Thus, on the one hand, the very precise and internationally standardised terminology in anatomy rests on Greek and Latin word bases, while, on the other hand, clinical sciences and especially those that evolve rapidly, such as molecular biology, genetics, and radiology, have a large influx of anglicisms and untranslated English words. The influence of foreign languages is most visible at the lexical level, but it also occurs at the grammatical level. Namely, the adaptation of loanwords, which is not always in line with the norms of the standard language and terminology but is often influenced by foreign language patterns, word formation models and elements, gives rise to numerous word formation variants and syntactic terminological variants. These variants, in addition to lexical variants, cause a sort of terminological chaos in professional texts. Word formation variants are particularly common in the case of adjective components of multiword terms in biomedicine. A wide choice of adjective suffixes, parallel formation with both domestic and foreign suffixes, the lack of distinction between the grammatical meaning of adjectives (descriptive adjectives versus relative adjectives) and the choice of an inappropriate word base result in numerous synonym and paronym variants. Terminology papers have so far examined noun structures, leaving adjectives neglected. Although syntactically dependent, adjectives express distinctive features of terms and play a classifying role in terminological systems, by establishing hierarchical and partitive relationships. However, traditional terminological dictionaries do not recognise the role of the adjective in the categorisation of terms, and adjectives very rarely appear as self-standing dictionary entries. When they do appear, there is usually no reference to the multiplicity of their meanings, their definition does not correspond to their morphological form and their combining potential is not adequately represented. The objective of this study was to determine the conformity of the suffixal adjective derivatives in the multi-word terms from the field of biomedicine to the norms of the Croatian standard language and terminology, based on examples from a specialised corpus. Particular attention was paid to the semantic aspect, i.e. to the differences and equivalencies in the meaning of parallel adjective derivatives. The following hypotheses served as the starting point: 1. Modern Croatian biomedical terminology is based on international loanwords and English loanwords, which are often not aligned with the Croatian standard language system, resulting in terminological disorder. 2. The derivation of adjectives from the same word bases by different suffixes and the choice of inappropriate basesin the word formation process result in numerous grammatical synonyms and paronyms. 3. Uncertainty in the formation of suffixal adjective derivatives leads to terminological inconsistencies and imprecision of meaning. In this research of suffixal adjective derivatives in biomedical terminology, the language in use and the standard language and terminology were analysed. The corpus on which the study was conducted was divided into two sub-corpora. The first sub-corpus consisted of scientific-expert journals, where written communication among professionals takes place and which cover all scientific areas in the field of biomedicine: basic and clinical medical sciences, public health and healthcare, basic and clinical neuroscience, veterinary medicine, dentistry, and pharmacy. Terminological candidates, i.e., adjective derivatives found in two or more derivative variants, were extracted from this sub-corpus by the Sketch Engine language corpus tool. The second sub-corpus consisted of professional monolingual, bilingual and multilingual donaries as reference literature containing the basic corpus of biomedical concepts, from which conclusions can be drawn about the normative status of certain terminological units. The second sub-corpus also included the Croatian terminology base Struna and modern general language dictionaries. These terminology registers from the second sub-corpus were used to examine the word formation variability of adjectives extracted from the first sub-corpus as well as to do a terminographic and lexicographic analysis. This paper is divided into two parts, a theoretical part and an analysis of the specialised corpus. The theoretical part gives a brief overview of the evolution of the science of terminology, and its general and modern theories. Special attention is paid to the terminology work in Croatia, from its onset prior to the standardisation of terminology, to the first terminological dictionaries up until the modern day and the development of the terminological base called Struna that restarted the standardisation of the terminology of different professions at an institutional level. The differences between general and special language, scientific and professional language, and professional language and professional jargon are explained. In addition to a brief overview of the history of biomedical terminology in Croatia, a description of contemporary biomedical terminology is also given, with a focus on foreign languages' lexical, syntactical and word formation impacts. The Greek and Latin terminological heritage is analysed from the aspect of simplicity, rationality and efficiency of international loanwords, their great capacity to form words and to enable better communication among professionals and scientists from different linguistic backgrounds. The influence of the English language is described in light of the growing number of untranslated terms and mechanically translated terms that often do not comply with the word formation and syntactic norms of the Croatian language. The use of literal translations is also an issue, which is particularly the case with the English terminology created by metaphorisation, whose metaphoricity is lost in translation into another language. International loanwords and English-based loanwords should comply with the norms of the Croatian standard language and its terminological principles. In this paper, examples from biomedical terminology are used to explain the terminological principles that must be followed in the creation of terms. Biomedical terms are also used to describe the way how words are derived and how they evolve. Adjectives in the Croatian general language are divided into descriptive and relative adjectives, and this distinction between them is also indicated by their derivational suffixes. For example, a descriptive Croatian adjective with the suffix –an (septičan (septic) – septična rana (septic wound)) and a relative Croatian adjective with the suffix –ski (septički (septic) – septički šok (septic shock)) are both derived from the noun sepsa (sepsis). Adjective derivatives, which both in general language and biomedical terminology mostly arise through suffixation, in biomedicine are mainly formed from foreign word bases. Croatian and foreign suffixes are then added to these bases, so one adjective is often formed by multiple suffixes. The variants from the noun parenhim (parenchyma) thus include parenhimni (parenchyma), parenhimski parenchyma), parenhimalni (parenchymal) and parenhimatozan (parenchymatous), of which the first two are formed by Croatian suffixes and the second two by adopted Latin suffixes. Besides that, the first three variants are relative adjectives and the fourth variant is a descriptive adjective. The formation of adjectives also often happens by the use of different derivatives from the same basic word. Derivative synonyms thus occur due to an incorrect choice of the basic word. For example, the paronymous adjectives genski (gene, from gene), genetski (genetic, from genesis) and genetički (genetic from genetics) or imunosni (immune, from immunity) and imunološki (immunologic, from immunology) are quite often used incorrectly. Due to the lack of knowledge about the word base and the derivation of adjectives by different suffixes, the terminology created is not only incompatible with the terminological principles of the Croatian standard language but the incorrect choice of the word base may also lead to a change in meaning. It happens that lexemes that are indeed paronyms and that should not be substituted in the same context are used as synonyms. This is particularly true for biomedical discourse, where such use must be avoided because biomedical discourse belongs to the scientific functional style, whose essential characteristics are the pursuit of accuracy, unambiguity, clarity, and precision of the content. Adjectives are also used to express the distinctive features of concepts, and, by establishing hierarchical and partitive relationships, they play a classifying role in various terminological systems. It is, therefore, important what morphological form, i.e. word formation pattern is used. Adjective variants extracted from the corpus were classified according to the motivation for their creation as follows: 1. Variants resulting due to parallel derivation by Croatian and foreign suffixes 2. Variants created by derivation from the full and abbreviated word base 3. Variants created by the synonymous use of the suffixes –ni and –ski 4. Variants created by the synonymous use of the verb participle and relative adjectives 5. Variants with different word bases 6. Variants created by the synonymous use of possessive and relative adjectives. The first group of adjectives includes mostly synonym variants that are formed by adopted Latin and Croatian suffixes in parallel. In line with the terminological principles, it is recommended that, when borrowing a term, only the word base is to be borrowed and derivatives are to be formed by adding Croatian suffixes if it does not lead to a change of meaning. Namely, there is a certain number of adjective derivatives, in which the grammatical and lexical meaning of the adjective differs depending on whether they are formed by adopted Latin or Croatian suffixes. For example, the descriptive adjective with the foreign suffix – ativan (oksidativan (oxidative) – oksidativna tvar (oxidative matter), a compound that possesses oxidative characteristics) and the relative adjective with the Croatian suffix –ski (oskidacijski (oxidation) – oksidacijsko oštećenje (oxidation damage), damage caused by oxidation) are both derived from the noun oksidacija (oxidation). The grammatical and semantic analysis of this adjective group has shown that suffixes play a distinct role, i.e. that certain adopted Latin suffixes may form descriptive adjectives (e.g. suffixes –(at)ivan, (at)ičan, –(at)ozan, –atoran, in derivatives hemoragičan (haemorrhagic), kolestatičan (cholestatic), regenerativan (regenerative), kompresivan (compressive), parenhimatozan (parenchymatous), membranozan (membranous), cirkulatoran (circulatory)), and that their Croatian equivalent suffixes –ni and –ski form relative adjectives hemoragijski (hemorrhagic), kolestatski (cholestatic), regeneracijski (regeneration), kompresijski (compression), parenhimni (parenchymal), membranski (membrane), cirkulacijski (circulatory)). Given the terminological recommendation that adjectives are to be formed with Croatian suffixes, it is easy to choose an adjective variant that is in conformity with the Croatian language standard. However, this proves to be much more difficult in adjectives in which the meaning of the noun from which they are derived and the parallel formation by synonymous foreign suffixes enable the breaking up of the synonym relations of the words with the same root. In biomedical terminology, adjectives derived from abstract female verbal nouns are most prone to this type of breaking up of synonym relations. These adjectives are formed from verbs with the noun suffixes –acija and –ija and are used to name diseases and conditions, pathological and physiological processes in the organism, and diagnostic and therapeutic procedures (infekcija (infection), ishemija (ischaemia), dilatacija (dilatation), proliferacija (prolipheration), etc.). The second group includes adjectives derived from nouns ending in –ik and –ika (probiotik (probiotic) > probiotski (probiotic) > probiotički (probiotic), farmakokinetika (pharmacokinetics) > farmakokinetski (pharmacokinetic), farmakokinetički (pharmacokinetic). They are scarce, and the recommendation is that they be formed from the full base. The distribution of suffixes –ni and –ski in adjective derivatives usually depends on whether they belong to the animate or inanimate category and on their respective sounds. Although for some derivatives it is recommended that they be formed by the suffix –ni since the adjective refers to an inanimate thing and since the sounds in that respective word allow it, the derivation by the suffix –ski prevails in use (e.g., enzimski (enzymic), sistemski (systemic)). The use of a verb participle in an adjective function is strongly influenced by the English language and its syntactic models (luteinising hormones – luteinizirajući hormon, angiotensinconverting enzyme – angiotenzinkonvertirajući enzim). In such cases, it is recommended that the adjective be derived from the verbal noun ending with –acija (luteinizacija (luteinisation) > luteinizacijski hormon (luteinisation hormone) or that it be built with the relative pronoun (enzim koji pretvara angiotenzin (an enzyme that converts angiotensin)). Variants with different bases result in paronyms that are misused as synonyms. These are, for example, the paronym pairs endemski (endemic) and endemijski (endemic), imunosni (immune) and imunološki (immunological). Although unambiguity is usually ensured through the context and the meaning of the base form is redundant, the correct choice of both the base and the suffix is needed for terminology in order to build a coherent system and not to breach the norm. The synonymous use of possessive and relative adjectives is observed in cases when it is not recognised whether the adjective should denote belonging (terapeutov stolac (therapist’s chair)) or it should have the meaning of a relative adjective (terapeutski stolac (therapeutic chair). Also, synonymous use is observed in chemical terms where chemical compounds are commonly compiled with a possessive adjective (kalcijev klorid (calcium chloride), ugljikov dioksid (carbon dioxide)). However, in cases other than chemical compounds, a relative adjective is used (kalcijski i natrijski kanali (calcium and sodium channels), dušična i ugljična kiselina (nitric and carbonic acid)). The browsing of terminological and general language dictionaries showed the same variability of adjectives as in scientific-expert journals. In some dictionaries, the tendency to be aligned with the language standard and terminological norm can be observed. Thus the Dictionary of Latin and Croatian Medical Vocabulary (Loknar 2003) favours adjective translation equivalents over any other equivalents, while the English-Croatian Medical Dictionary (Jernej 2006, 2009) favours the forms with –ski over the adopted Latin adjectives, and the forms with –ni over the ones on –ski. However, there is no coherence in including adjectives in the terminological syntagms, and adjectives with the same root can have different forms in different terms, although their grammatical and lexical meaning remains the same (e.g., kompresijski ileus (compression ileus) and kompresivna atelektaza (compressive atelectase)). The lexical compatibility and combination potential are often ignored, and this results in nonvalid syntagms such as an imuno protutijelo (immune antibody – resistant antibody) instead of an imunosno protutijelo (antibody of the immune system) as well as an aseptička gaza (aseptic gauze (relative adjective) instead of an aseptična gaza (descriptive adjective – sterile gauze). The definitions of adjective entries in dictionaries do not always correspond to their meaning and so it often happens that the relative form of the adjective has the definition of the descriptive adjective (opturacijski (obturation) – ‘that which blocks’ instead of the descriptive variant opturativan (obturational)), while the descriptive form of the adjective has the definition of the relative adjective (septičan (septical – ’that which relates to sepsis‘, instead of the variant septički (septic)). General language dictionaries contain only a smaller part of the terms extracted from the corpus. These dictionaries show attempts to differentiate between the descriptive and relative forms of adjectives and that the definition should correspond to the morphological form of the derivative. In the last part of the paper, adjective derivatives are normatively ranked in accordance with the terminology principles and the word formation norm of the Croatian standard language, and they are accompanied by an annotation on whether they are recommended, admitted or not recommended terms. Adjectives are also accompanied by definitions, taking into account the distinction between their descriptive and relative meaning. This paper proves the set hypotheses about the presence of international loan words and English loan translations in biomedical terminology, which are not aligned with the language and terminological norms of the Croatian language. This often gives rise to numerous synonym and paronym forms of adjectives, causing uncertainty in forming and using biomedical terms, imprecision of their meaning and their terminological disparity. The conclusion is that the role of adjectives in biomedical terminology is of extreme importance because adjectives enable the establishment of relations between concepts and their differentiation. Differentiating among synonyms, explaining the meaning of adjective variants and stating the correct syntagmatic relations in the terminographic analysis of adjectives, both as the grammatical word category and as a lexeme that is often the carrier of the main semantic information, would therefore be extremely useful. Adjectives analysed this way would contribute to their more systematic use in practice, i.e. to reducing the deviation from the word formation and lexical norms in the scientific, professional and written language in the area of biomedicine.