any of a genus (Sargassum, family Sargassaceae) of floating brown algae (order Fucales) found in tropical seas and having a main stem with flattened outgrowths like leaves, and branches with berry-like air sacs; gulfweed
pl. -·sosor sargasso weed
Origin of sargassumModern Latin ; from Portuguese sargaço ; from sarga, kind of grape
Origin of sargassumNew Latin Sargassum, genus name, from sargasso.
- Any of many brown algae of the genus Sargassum; gulfweed