[1] : The Collaborative International Dictionary of English v.0.48

physalia \physa"lia\, prop. n. nl., fr. gr. fysalli`s a
   bladder, fr. fy^sa a bellows. zool.
   a genus of large oceanic siphonophora which includes the
   portuguese man-of-war.
   1913 webster

   note: it has a large air sac, or float, with a sail-like
         crest on its upper side. numerous zooids of different
         kinds are attached to the under side of the float. some
         of the zooids have very long tentacles; some have a
         mouth and digest food; others produce gonophores. the
         american species physalia arethusa is brilliantly
         colored, the float being pink or purple, and bright
         blue; the zooids blue. it is noted for its virulent
         stinging powers, as well as for its beautiful colors,
         graceful motions, and its ability to sail to windward.
         1913 webster
see also:
physalia arethusa 

Physalia >> P Words
Physalia, definition of term: Physalia
physalia_pag1.html

Arethusa >> A Words
Arethusa, definition of term: Arethusa
arethusa_pag1.html