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
Michael Le PageThe 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
Elyse Inamine2
: a mass or growth of seaweeds
… soft crabs were easily visible in the seaweed, because the water was crystal clear then.—Keith Walters
Keith Walters3
: harvested seaweed or seaweed parts used especially as food, fertilizer, and in cosmetics
… sushi rolls wrapped in thin sheets of dried seaweed …—Jane Snow
Jane SnowExamples of seaweed in a Sentence
Recent Examples on the Web
Miscellaneous foods like seaweed and iodized salt contain iodine which is important for thyroid functioning and brain development during pregnancy and infancy.23 Seaweed is also considered a (nondairy) source of calcium and contains vitamin B12, and omega-3 fatty acids.
—Allison Herries, Verywell Health, 4 Jan. 2025
Chicken katsu, which is coated with bread crumbs and sliced, is a mainstay of Hawaiian restaurants, along with Spam musubi, a brick of rice topped with luncheon meat and wrapped in edible seaweed, and Hawaiian macaroni salad.
—Fielding Buck, Boston Herald, 1 Jan. 2025
This year’s design includes a 55-foot replica of the USS Princeton aircraft carrier, a Sikorsky Black Hawk helicopter made of seaweed and parsley, a laptop with a working QR code that will provide information for the nonprofit and a pyrotechnic feature.
—Alicia Victoria Lozano, NBC News, 31 Dec. 2024
When grazing beef cattle were fed seaweed supplements, their methane emissions dropped by nearly 40 percent.
—Sarah Kuta, Smithsonian Magazine, 3 Dec. 2024
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Allison Herries, Verywell Health, 4 Jan. 2025
Chicken katsu, which is coated with bread crumbs and sliced, is a mainstay of Hawaiian restaurants, along with Spam musubi, a brick of rice topped with luncheon meat and wrapped in edible seaweed, and Hawaiian macaroni salad.
—Fielding Buck, Boston Herald, 1 Jan. 2025
This year’s design includes a 55-foot replica of the USS Princeton aircraft carrier, a Sikorsky Black Hawk helicopter made of seaweed and parsley, a laptop with a working QR code that will provide information for the nonprofit and a pyrotechnic feature.
—Alicia Victoria Lozano, NBC News, 31 Dec. 2024
When grazing beef cattle were fed seaweed supplements, their methane emissions dropped by nearly 40 percent.
—Sarah Kuta, Smithsonian Magazine, 3 Dec. 2024
See all Example Sentences for seaweed
Dictionary Entries Near seaweed
Cite this Entry
“Seaweed.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/seaweed. Accessed 8 Feb. 2025.
Copy CitationKids Definition
seaweed
noun
sea·weed
-ˌwēd 
: a plant growing in the sea
especially
: a marine alga (as a kelp)
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