Liliaceous \Lil`i*a"ceous\ (l[i^]l`[i^]*[=a]"sh[u^]s), a. [L. liliaceus, fr. lilium lily. See Lily.]

(Bot.)
   (a) Of or pertaining to a natural order of which the lily, tulip, and hyacinth are well-known examples.
   (b) Like the blossom of a lily in general form.

Source: Webster's Revised Unabridged Dictionary (1913)