means A shrub or small tree bearing fragrant clusters of pale purple flowers, or the soft purple color named for those blooms.

from From French 'lilac,' borrowed from Spanish 'lilac,' which came from Arabic 'lilak' — itself adopted from Persian 'nilak,' meaning 'bluish,' a diminutive of 'nil,' 'blue' or 'indigo.' So the word traveled west across centuries, carrying the memory of a blue-violet color before it ever settled on this particular fragrant bush, which Europeans first encountered via the Ottoman world.