hydroid

1 of 2

adjective

hy·droid ˈhī-ˌdrȯid

: of or relating to a hydrozoan

especially : resembling a typical hydra

hydroid

2 of 2

noun

: hydrozoan

especially : a hydrozoan polyp as distinguished from a hydrozoan medusa

Examples of hydroid in a Sentence

Recent Examples on the Web

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Adjective

Scientists are divided over whether a creature sitting near the wheel — which resembles an ostrich feather crossed with a Christmas tree — is a hydroid or a black coral. —New York Times, 11 Mar. 2022

Coastal podded hydroid Aglaophenia pluma, open-ocean Planes crab and open-ocean Lepas gooseneck barnacles colonize a piece of floating debris. —NBC News, 3 Dec. 2021

Noun

The crab had camouflaged and armed itself with tiny hydroids known as Tubularia. —Cecilia Rodriguez, Forbes, 26 Nov. 2024 The first three all originate in the Far East, while Bengals are a hydroid cross between cats and Asian leopard cats. —Jennifer Ouellette, Ars Technica, 4 Sep. 2024 Polyps are part of the life cycle of jellyfish and the related group of animals known as hydroids. —Aspen Pflughoeft, Miami Herald, 20 Feb. 2024 Common coastal stowaways included amphipods, isopods, hydroids and bryozoans, most of which originated from the northwest Pacific. —Tim Brinkhof, Discover Magazine, 25 Nov. 2023 The rock was also lined with wispy filaments, perhaps a component of the bacterial mats, or perhaps a peculiar animal known as a hydroid. —Matt Simon, Wired, 15 Feb. 2021 Some grow algae and hydroid gardens on their backs, others can change color at will, and one, the decoy scorpionfish, has a lure on its dorsal fin that resembles a tiny, swimming fish. —Troy Farah, Smithsonian, 29 Mar. 2018 The nudibranch, besides using the hydroids for habitat, regularly consume its home colony’s polyps. —Sid Perkins, Science | AAAS, 31 Oct. 2017 In the wild, these slugs are known to feed on hydroids, an invertebrate marine organism. —Brigit Katz, Smithsonian, 4 Nov. 2017

Word History

Etymology

Adjective

ultimately from New Latin Hydra

First Known Use

Adjective

circa 1864, in the meaning defined above

Noun

1865, in the meaning defined above

Time Traveler

The first known use of hydroid was circa 1864

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hydro-hotel

hydroid

Hydroida

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Cite this Entry

Style

“Hydroid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hydroid. Accessed 31 Mar. 2025.

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Kids Definition

hydroid

1 of 2 adjective

hy·droid ˈhī-ˌdrȯid

: of or relating to the hydrozoans

especially : resembling a hydra

hydroid

2 of 2 noun

: hydrozoan

especially : a hydrozoan polyp in contrast to a hydrozoan jellyfish

Medical Definition

hydroid

1 of 2 adjective

hy·droid ˈhī-ˌdrȯid

: of or relating to a hydrozoan

especially : resembling a typical hydra

hydroid

2 of 2 noun

: hydrozoan

especially : a hydrozoan polyp as distinguished from a medusa

hydroid

adjective

noun

Examples of hydroid in a Sentence

Word History

Browse Nearby Words

Cite this Entry

Kids Definition

Medical Definition

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hydroid

adjective

noun

Examples of hydroid in a Sentence

Word History

Rhymes for hydroid

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Kids Definition

Medical Definition

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More from Merriam-Webster

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