[li.lac] n [obs. F (now lilas), fr. Ar lilak, fr. Per nilak bluish, fr. nil blue, fr. Skt nila dark blue] (1625) 1 a: a European shrub (Syringa vulgaris) of the olive family that is often an escape in No. America and has cordate ovate leaves and large panicles of fragrant pink-purple or white flowers b: a tree or shrub congeneric with the lilac
2: a variable color averaging a moderate purple