The article focuses on the analysis of the nominative fi eld of the sub-concept ΜΑΝΙΑ in the Ancient Greek language, which is one of the components of the macro-concept DISEASE, covering the entire complex of signs which characterize abnormal human behavior. For the completeness of the analysis, a number of methods were used, in particular, the descriptive one, the method of conceptual, etymological and component analyses, and linguistic modeling. As a result of the study, it was estab lished that the mentioned nominative fi eld is monocentric with a clearly defi ned core and paranuclear and peripheral zones. The core consists of the lexemes formed from the root μαν- (μανία, μανικóς, μαίνομαι together with composi tes), which are the most frequent ones and most fully realize the “lack of mental adeq uacy” sema. The lexeme μανια is a term commonly used both in medical texts and in the texts of other genres. In various contexts, it denotes extreme and excessive behavior and mental disorders. The paranuclear zone includes lexemes which characterize various deviations from the norm and differ from the keyword-name of the concept in shades of meaning. As a result of the semanti c analysis, the lexemes were divided into four microfi elds: 1) “inadeq uacy of thinking and actions” (ἀβελτερία, ἀλογιστία, ἀεσιφροσύνη, ἀλλοφρονέω, etc.); 2) “state of aff ect” (ἀδημονέω, δαιμονάω, λύσσα, μαργότης, ἔκστασις, ἔκστασις, etc.); 3) “exaltation” (βακχεύω and verbs derived from it, βάκχευσις, ἐνθουσιάζω, ἐνθουσίασις, etc.); 4) “morbid mental state” (παρανοέω, παράνοια, παραφροσύνη, φρενιτίζω, etc.). The paranuclear zone also includes the commonly used lexemes to denote disease (νόσος, ἀρρωστία, ἀσθένεια) specifi ed by the nouns φρήν, νοῦς, ψυχή. In the peripheral zone, the near and far periphery is distinguished. The fi rst includes words in which the “lack of mental adequacy” seme is secondary although motivated by the main lexical meaning (e.g., ἀάω, ἀνόητος, ἄλογος). The far periphery is represented by the lexemes which acquire close (or identical) to the semantics of the nuclear lexeme meanings only in a certain context; however, these meanings are not motivated by their basic lexical semantics, arising as a result of metaphorization or ellipsis (eg: ἄλη, ἐλλέβορος, πῦρ, λῆρος, παρακοπή, etc.). Key words: Ancient Greek language, nominative fi eld, sub-concept, lexeme, core, periphery.