sar·​gas·​sum sär-ˈga-səm How to pronounce sargassum (audio)
: 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

Example Sentences

Recent Examples on the Web Hurricanes, spring break revelers, and sargassum seaweed are other pitfalls to plan around when visiting the Yucatan shores. Megan Wood, Travel + Leisure, 17 May 2023 Sargassum Large amounts of sargassum, or seaweed, are projected to hit Florida beaches this summer. Jennifer Borresen, USA TODAY, 1 May 2023 An estimated 200 tons of sargassum washed up on beaches along the Yucatán Peninsula this year. Sarah Bahari, Dallas News, 29 Apr. 2023 Here’s a look at this year’s sargassum seaweed bloom: WHAT IS SARGASSUM? Suman Naishadham, Anchorage Daily News, 22 Mar. 2023 Part of the problem now is that the amount of sargassum in the oceans has increased dramatically in the last 15 years or so. Dennis Pillion |, al, 17 Mar. 2023 The Atlantic Ocean is heavy on the sargassum A blob twice the width of the US is heading towards Florida's coast CNN’s Rosemary Church interviews a leading scientist about a massive seaweed blob twice the size of the US that’s headed for the Gulf of Mexico. Colby Hentges, CNN, 17 Mar. 2023 Scientists at the University of South Florida, with the help of the National Aeronautics and Space Administration, have been tracking the bloom of sargassum, a type of brown seaweed, using satellites. Peter Charalambous, ABC News, 14 Mar. 2023 Like all seaweed, sargassum is also excellent at sequestering carbon dioxide and producing oxygen via photosynthesis. Stephen C. George, Discover Magazine, 1 Apr. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'sargassum.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


borrowed from New Latin, borrowed from Portuguese sargaço sargasso

First Known Use

circa 1890, in the meaning defined above

Time Traveler
The first known use of sargassum was circa 1890

Dictionary Entries Near sargassum

Cite this Entry

“Sargassum.” Dictionary, Merriam-Webster, Accessed 30 May. 2023.

Kids Definition


sar·​gas·​sum sär-ˈgas-əm How to pronounce sargassum (audio)
: 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

More from Merriam-Webster on sargassum

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