cauliflower n.

Proto-Indo-European root meaning "to thrive, bloom," possibly a variant of PIE root *bhel- (2) "to blow, swell."

It forms all or part of: blade; bleed; bless; blood; blow (v.2) "to bloom, blossom;" bloom (n.1) "blossom of a plant;" bloom (n.2) "rough mass of wrought iron;" blossom; cauliflower; chervil; cinquefoil; deflower; defoliation; effloresce; exfoliate; feuilleton; flora; floral; floret; florid; florin; florist; flour; flourish; flower; foil (n.) "very thin sheet of metal;" foliage; folio; folium; gillyflower; Phyllis; phyllo-; portfolio; trefoil.

It is the hypothetical source of/evidence for its existence is provided by: Greek phyllon "leaf;" Latin flos "flower," folio, folium "leaf;" Middle Irish blath, Welsh blawd "blossom, flower;" Gaelic bile "leaflet, blossom;" Old English blowan "to flower, bloom."

"cabbage," a dialectal survival of Middle English col, from late Old English cawel, or perhaps from or influenced by cognate Old Norse kal. Both words are from Latin caulis "stem, stalk" (which in Vulgar Latin replaced brassica as the usual word for "cabbage"), from Proto-Italic *kauli- "stalk," from PIE root *(s)kehuli- "stem of a plant, stalk" (source also of Old Irish cual "faggot, bundle of sticks," Greek kaulos "stem, stalk, pole," Armenian c'awl "stalk, straw," Old Prussian kaulan, Lithuanian káulas "bone").

Latin caulis "cabbage" is the source also of Italian cavolo, Spanish col, Old French chol, French chou; it also was borrowed elsewhere in Germanic, for example Swedish kål, Danish kaal, German Kohl, Dutch kool.