/ ˈlaɪlək; NAmE / noun
1.
[ U , C ] a bush or small tree with purple or white flowers with a sweet smell that grow closely together in the shape of a cone
2.
[ U ] a pale purple colour
► lilac adjective :
a lilac dress
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WORD ORIGIN
early 17th cent.: from obsolete French , via Spanish and Arabic from Persian līlak , variant of nīlak bluish, from nīl blue.