Source : Webster's Revised Unabridged Dictionary (1913)

Siphonophora \Si`pho*noph"o*ra\, n. pl. [NL., fr. Gr. ??? a
   siphon + ???? to bear.] (Zo["o]l.)
   An order of pelagic Hydrozoa including species which form
   complex free-swimming communities composed of numerous zooids
   of various kinds, some of which act as floats or as swimming
   organs, others as feeding or nutritive zooids, and others as
   reproductive zooids. See Illust. under {Physallia}, and
   {Porpita}.

Source : WordNet®

Siphonophora
     n : marine colonial hydrozoans [syn: {order Siphonophora}]