n. The quality of being synonymous, or of expressing the same meaning by different words.n. In rhetoric, a figure by which words of the same meaning are used to amplify a discourse.n. A thing of the same name.n. A system of synonyms; a collection of synonyms; also, the study of synonyms; the use of synonyms in expressing different shades of meaning; the discrimination of synonyms; especially, in natural history, the sifting of synonyms to determine the onyms.