Source : Webster's Revised Unabridged Dictionary (1913)

Centaurea \Cen`tau*re"a\, n. [NL. See {Centaury}.] (Bot.)
   A large genus of composite plants, related to the thistles
   and including the cornflower or bluebottle ({Centaurea
   Cyanus}) and the star thistle ({C. Calcitrapa}).

Cornflower \Corn"flow`er\ (-flou`?r), n. (Bot.)
   A conspicuous wild flower ({Centaurea Cyanus}), growing in
   grainfields.

Source : WordNet®

Centaurea cyanus
     n : an annual Eurasian plant cultivated in North America having
         showy heads of blue or purple or pink or white flowers
         [syn: {cornflower}, {bachelor's button}, {bluebottle}]