- any of various shrubs belonging to the genus Syringa, of the olive family, as S. vulgaris, having large clusters of fragrant purple or white flowers: the state flower of New Hampshire.
- pale reddish purple.
- having the color lilac.
- any of various Eurasian oleaceous shrubs or small trees of the genus Syringa, esp S. vulgaris (common lilac) which has large sprays of purple or white fragrant flowers
- French lilac another name for goat's-rue (def. 1)
- a light or moderate purple colour, sometimes with a bluish or reddish tinge
- (as adjective)
