a form of cultivated plant, Brassica oleracea botrytis, of the mustard family, whose inflorescence forms a compact, usually whitish head. Compare broccoli.
2.
this head, used as a vegetable.
Origin: 1590–1600; < L cauli(s) cole+ flower; r. coleflorie < It ca(v)olfiore, equiv. to cavol cole + fiore < L flōri- (s. of flōs) flower
cau·li·flow·er (kô'lĭ-flou'ər, kŏl'ĭ-) n. An herb (Brassica oleracea var. botrytis) in the mustard family, related to the cabbage and broccoli and having a whitish undeveloped flower with a large edible head.
[Probably alteration (influenced by flower) of New Latin cauliflōra : Latin caulis, stem + Latin flōs, flōr-, flower; see flower.]
1597, originally cole florye, from It. cavoli fiori "flowered cabbage," pl. of cavolo "cabbage" + fiore "flower" (from L. flora, q.v.). First element from L. caulis "cabbage," borrowed into Gmc. and source of cole in Du. "cole slaw" and of Scot. kale. The front end of the word was re-Latinized. The boxer's cauliflower ear is from 1907.