seahorse

American  

[see-hawrs] / ˈsiˌhɔrs /

Or sea horse

noun

1. any fish of the genus Hippocampus, of the pipefish family, having a prehensile tail, an elongated snout, and a head bent at right angles to the body.

2. a fabled marine animal with the foreparts of a horse and the hind parts of a fish.

3. a walrus.

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Etymology

Origin of seahorse

First recorded in 1425–75; late Middle English sehors, possibly meaning “walrus”; compare German Seeross; see origin at sea ( def. ), horse

Explanation

A seahorse is a tiny fish with a vaguely horse-shaped head. Seahorses swim upright, with their curled tails pointing down. Seahorses look different from most fish, with hard, bony exteriors and long snouts. They're also different from almost all other animals because male seahorses give birth to babies, after carrying eggs deposited by the female. The scientific genus of seahorses is Hippocampus, from the Ancient Greek words hippos, "horse," and kampos, "sea monster." There's also a section of the human brain called the hippocampus, named for its resemblance to the seahorse.

Example Sentences

Last night, Lauper got a new tattoo of a seahorse on her arm.

From Los Angeles Times • Oct. 8, 2025

It said the site supported specialised communities of animals, seaweeds and the rare short-snouted seahorse.

From BBC • Aug. 28, 2025

Posting on the website, they provide information about which species of seahorse, when and where in the world they saw it, its habitat, and its depth.

From Science Daily • Mar. 25, 2024

In 2020, these seahorses were named the second most endangered kind of seahorse in the world.

From NewsForKids.net • Aug. 3, 2023

In time my little black ship will fly as high as Velaryon’s seahorse or Celtigar’s red crabs.

From "A Clash of Kings" by George R.R. Martin