Siamese fighting fish

American  

noun

1. a labyrinth fish, Betta splendens, that has been bred for centuries to develop brilliant coloration, very long fins, and pugnacity.

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Siamese fighting fish British  

noun

1. a brightly coloured labyrinth fish, Betta splendens, of Thailand and Malaysia, having large sail-like fins: the males are very pugnacious

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Etymology

Origin of Siamese fighting fish

First recorded in 1930–35

Example Sentences

A lifelong animal lover, Kerry also has dogs, cats and a Siamese fighting fish called Gomez - but warned axolotls require careful upkeep.

From BBC • Apr. 26, 2026

Other species making use of color for courtship include the fan-throated lizard, with a wattle of iridescent blue and orange, and the Siamese fighting fish, its tail bristling with blood-orange finnage.

From New York Times • Dec. 31, 2020

In the first story, a Paris lawyer becomes fixated on her Siamese fighting fish, a male-female pair, determined to preserve their harmonious existence as her marriage continues “its gradual course toward putrefaction.”

From New York Times • Jun. 25, 2014

Siamese fighting fish are bred to bring out their violent characters Siamese fighting fish take gulps of air from above water so they can continue to clash, say scientists.

From BBC • Nov. 29, 2012

The finer strains of Siamese fighting fish are products of artificial selection, bred for stamina as well as fighting prowess.

From Time Magazine Archive