Abbreviated Syn. n. pl. Synonyms. (- nimz). One of two or more words (commonly words of the same language) which are equivalents of each other; one of two or more words which have very nearly the same signification, and therefore may often be used interchangeably. See under Synonymous. All languages tend to clear themselves of synonyms as intellectual culture advances, the superfluous words being taken up and appropriated by new shades and combinations of thought evolved in the progress of society.