sinonym - n.
1 a word or phrase that means exactly or nearly the same as another in the same language (e.g. shut and close).
2 a word denoting the same thing as another but suitable to a different context (e.g. serpent for snake, Hellene for Greek) or containing a different emphasis (e.g. blindworm for slow-worm).
3 a word equivalent to another in some but not all senses (e.g. ship and vessel).

synonymic adj. synonymity n. [ME f. L synonymum f. Gk sunonumon neut. of sunonumos (as SYN-, onoma name): cf. ANONYMOUS]