The paper considers Portuguese for Audit and Accounting as a specific domain of knowledge and studies the terminological expressions, or terminological collocations, subject to Chernovaty's classification of terms, or according to Chaika ( , 2020, linguistic monomials as set term clusters in relevant terminologies, or languages for specific purposes (LSP). In order to demonstrate the application of methodology, this time it is Portuguese for Audit and Accounting, which serves to meet the objectives of the current study. The paper aims to reveal certain approaches to analyse the structure of the monomial in linguistics. Such approaches vary from the structural analysis of the set term cluster (monomial) by the number of components / elements in the structure, morphological class of the head term in the monomial structure, to their role in a sentence under a professional setting, as well as syntactic patterns as basic units of syntax, which are logically, grammatically, and semantically arranged. The result is unique inseparable conceptual (semantic) value of such monomials in Portuguese for Audit and Accounting. The list of approaches to study and analysis of the designated field and the respective material is not exhaustive. The examples of monomials in Portuguese for Audit and Accounting are selected from the Glossary of Terms, the Handbook of International Quality Control, Auditing, Review, Other Assurance, and Related Services Pronouncements validated by the International Auditing and Assurance Standards Board (IAASB). It is revealed that distinct similarities identified in the course of work with Portuguese for Audit and Accounting may take to relevant classifications attributable with the same set of criteria for the Ukrainian, English, German, Spanish languages as representatives of the Slavic, Germanic, and Romance families. The further prospect lies in performing comparative and contrastive analyses of the mentioned language material in respective LSP corpora.