sargasso

UK: /sɑːˈɡæsəʊ/ US: (sär gas′ō)

WordReference Random House Unabridged Dictionary of American English © 2026

sar•gas•so  (sär gas′ō), n., pl. -sos. 

1. Microbiology a gulfweed.

• Latin salicastrum, equivalent. to salic- (stem of salix) willow + -astrum, neuter of -aster -aster¹
• Portuguese, perh. special use of sargaço rockrose
• 1590–1600

Collins Concise English Dictionary © HarperCollins Publishers::

sargasso, sargasso weed / sɑːˈɡæsəʊ/ noun ( -sos)

1. another name for gulfweed, sargassum

Etymology: 16th Century: from Portuguese sargaço, of unknown origin

WordReference Random House Unabridged Dictionary of American English © 2026

sar•gas•sum  (sär gas′əm), n. 

1. Microbiology any seaweed of the genus Sargassum, widely distributed in the warmer waters of the globe, as S. bacciferum, the common gulfweed.

• Neo-Latin; see sargasso
• 1900–05

Collins Concise English Dictionary © HarperCollins Publishers::

sargassum / sɑːˈɡæsəm/, sargasso / sɑːˈɡæsəʊ/ noun

1. any floating brown seaweed of the genus Sargassum, such as gulfweed, of warm seas, having ribbon-like fronds containing air sacs

Etymology: 18th Century: from New Latin; see sargasso