plural seahorses
1
: any of a genus (Hippocampus of the family Syngnathidae) of small bony fishes that have the head angled downward toward the body which is carried vertically and are equipped with a prehensile tail
2
: a mythical creature half horse and half fish
3
: walrus

Illustration of seahorse

Illustration of seahorse
  • seahorse 1

Examples of seahorse 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.
Showing off import sheets related to bats, seahorses and other creatures, Tlusty illustrated how this works. — John Werner, Forbes.com, 30 Aug. 2026 So far this year, officials have confiscated more than 8,900 species, although a majority of those were crickets and young fish to feed animals including seahorses. — ABC News, 29 July 2026 Even the shape of the island—a 7-mile-long seahorse—belongs on a postcard. — Tara Massouleh McCay, Southern Living, 28 July 2026 There are shallow but rich dives; full-of-life, accessible wrecks; and thriving reefs, including my favorite spot, the unlikely cement plant, with seahorses and octopus reclining beneath its pier pilings—pilings that are fantastical once underwater. — Jonnie Bayfield, Condé Nast Traveler, 19 July 2026 See All Example Sentences for seahorse

Word History

First Known Use

15th century, in the meaning defined at sense 3

Time Traveler
The first known use of seahorse was in the 15th century

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Cite this Entry

“Seahorse.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/seahorse. Accessed 4 Oct. 2026.

Kids Definition

sea horse

noun
1
: a mythical animal half horse and half fish
2
: a small fish with bony plates covering its body and a head that looks like a horse's head
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