sargassum

noun

sar·​gas·​sum sär-ˈga-səm 

: any of a genus (Sargassum) of brown algae that have a branching thallus with lateral outgrowths differentiated as leafy segments, air bladders, or spore-bearing structures : gulfweed

Examples of sargassum in a Sentence

Recent Examples on the Web

What To Know Scientists documented more than 37 million metric tons of sargassum in May 2025, shattering previous records set just two years earlier, said USF's lab. —Sophie Clark, MSNBC Newsweek, 6 June 2025

In previous years, June continued to see increases of sargassum in most regions, according to the USF report. —Julia Jacobo, ABC News, 5 June 2025

The total mass of sargassum observed in the Caribbean Sea, western and eastern Atlantic and the Gulf of Mexico is about 37.5 million tons. —Alix Martichoux, The Hill, 4 June 2025

Florida's east coast and the Caribbean will continue to be inundated with sargassum, per the report. —Martin Vassolo, Axios, 6 May 2025

Word History

Etymology

borrowed from New Latin, borrowed from Portuguese sargaço sargasso

First Known Use

circa 1890, in the meaning defined above

Kids Definition

sargassum

noun

sar·​gas·​sum sär-ˈgas-əm 

: any of a genus of brown algae that have a leafy branching body and air bladders and that often grow in free-floating masses in the ocean