seaweed

[see-weed]

noun

1. any plant or plants growing in the ocean.

2. a marine alga.

seaweed

/ ˈsiːˌwiːd /

noun

1. any of numerous multicellular marine algae that grow on the seashore, in salt marshes, in brackish water, or submerged in the ocean

2. any of certain other plants that grow in or close to the sea

seaweed

1. Any of various red, green, or brown algae that live in ocean waters. Some species of seaweed are free-floating, while others are attached to the ocean bottom. Seaweed range from the size of a pinhead to having large fronds (such as those of many kelps) that can be as much as 30.5 m (100 ft) in length. Certain species are used for food (such as nori) and fertilizer, and others are harvested for carrageenan and other substances used as thickening, stabilizing, emulsifying, or suspending agents in industrial, pharmaceutical, and food products. Seaweed is also a natural source of the element iodine, which is otherwise found only in very small amounts.

2. See more at brown alga green alga red alga

Word History and Origins

Origin of seaweed¹

First recorded in 1570–80; sea + weed ¹

Example Sentences

To evaluate the effect of seaweed, researchers built controlled crawlways on the sand that simulated each hatchling's natural route.

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Some strategies use biological processes, such as increasing plankton or seaweed growth so they can take up carbon dioxide as they develop.

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Maloney provided exceptionally well-preserved seaweed fossils that are roughly one billion years old, collected from Yukon Territory, Canada.

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Another smelled like a pile of wet rope encrusted with seaweed and left to rot in the sun, and a nasty, fishy aroma it was.

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Among them is avoiding seaweed soup for lunch, as its slippery strands are believed to make students "slip" in the high-stakes test -- a superstition that has long shaped test-day menus.

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Related Words

• algae