seaweed

noun

sea·​weed ˈsē-ˌwēd How to pronounce seaweed (audio)
1
plural seaweeds : any of various aquatic and chiefly marine brown, red, or green algae (such as rockweed, gulfweed, and kelp) that often grow in masses, typically have leaflike blades (see blade entry 1 sense 2e), are usually anchored to a solid substrate (such as a rock) by holdfasts (see holdfast sense 2a), and include some (such as dulse, laver, and sea lettuce) that are used as food
… many seaweeds have floats called pneumatocysts, filled with oxygen or carbon dioxide.Michael Le Page
The word seaweed is broad and refers generally to marine macroalgae, which are algae living in salt or brackish water and visible to the eye.Elyse Inamine
2
: a mass or growth of seaweeds
… soft crabs were easily visible in the seaweed, because the water was crystal clear then.Keith Walters
3
: harvested seaweed or seaweed parts used especially as food, fertilizer, and in cosmetics
… sushi rolls wrapped in thin sheets of dried seaweedJane Snow

Examples of seaweed in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The seaweed note in this fragrance creates the oceanic atmosphere, and the salt accord takes it over the edge. Marci Robin, Allure, 27 Feb. 2025 Kelp is a type of seaweed, usually brown, that grows in tall stands beneath the surface of the ocean. Joshua Siskin, Orange County Register, 14 Feb. 2025 Another additive that has received widespread attention is seaweed, and its active ingredient bromoform. Marianne Krasny, Forbes, 13 Jan. 2025 Finally, seaweed extract helps moisturize the skin and give it a brighter glow. Kiana Murden, Vogue, 9 Jan. 2025 See All Example Sentences for seaweed

Word History

First Known Use

1577, in the meaning defined at sense 1a

Time Traveler
The first known use of seaweed was in 1577

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Cite this Entry

“Seaweed.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/seaweed. Accessed 13 Mar. 2025.

Kids Definition

seaweed

noun
sea·​weed -ˌwēd How to pronounce seaweed (audio)
: a plant growing in the sea
especially : a marine alga (as a kelp)

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