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

Maybe you have looked at the clouds and imagined a sailboat, a seahorse, or even your great-aunt Rosemary staring back at you.

From Science Daily • May 14, 2026

Designed by Charles T. Meier and engineered by project manager Kyle Amerine, the massive seahorse nodded as it coached over a dozen fin-flapping baby sea creatures as they performed a synchronized swimming routine.

From Los Angeles Times • Jan. 3, 2026

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

From BBC • Aug. 28, 2025

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

From NewsForKids.net • Aug. 3, 2023

I look down at where my seahorse tattoo should be.

From "They Both Die at the End" by Adam Silvera