sargasso

from WordNet (r) 3.0 (2006)

sargasso
    n 1: brown algae with rounded bladders forming dense floating
         masses in tropical Atlantic waters as in the Sargasso Sea
         [syn: {gulfweed}, {sargassum}, {sargasso}, {Sargassum
         bacciferum}]

from The Collaborative International Dictionary of English v.0.48

Sargasso \Sar*gas"so\, n. [Sp. sargazo seaweed.] (Bot.)
   The gulf weed. See under {Gulf}.
   [1913 Webster]

   {Sargasso Sea}, a large tract of the North Atlantic Ocean
      where sargasso in great abundance floats on the surface.
      [1913 Webster]