From the point of view of the lexicographic tradition, antonymy designates opposite terms. The attempts to treat antonyms from the perspective of the logical opposition failed to bring around the expected results in the strict delimitation of the lexical antonymy from the other types of opposite notions, because those characteristics that need to be considered as contrary have not been established yet. The linguistic criterion is contrary to this point of view as it takes into consideration the lexical distribution and the contextual manifestation of the antonyms in their syntagmatic use of speech: in antonymic contexts of a certain type, with a certain syntactic structure having identical combinatory possibilities. The research of the development of antonymy relations through the derivative links of the opposable terms is an essential aspect of the study of the relations of antonymy in terminologies. The analysis of various examples from the French legal vocabulary proves the fact that antonymy is a pertinent linguistic phenomenon, especially for the terms with a strong qualifying value. The adjectival terms and the nouns formed by adding prefixes act like antonyms under the conditions of changing the contradiction in contrariety.