Source : Webster's Revised Unabridged Dictionary (1913)

Cosmos \Cos"mos\, n. (Bot.)
   A genus of composite plants closely related to {Bidens},
   usually with very showy flowers, some with yellow, others
   with red, scarlet, purple, white, or lilac rays. They are
   natives of the warmer parts of America, and many species are
   cultivated. {Cosmos bipinnatus} and {C. diversifolius} are
   among the best-known species; {C. caudatus}, of the West
   Indies, is widely naturalized.