killifish

noun

kil·​li·​fish ˈki-li-ˌfish 

1

: any of a family (Cyprinodontidae) of numerous small oviparous fishes much used as bait and in mosquito control

2

: any of various live-bearers (family Poeciliidae)

Examples of killifish in a Sentence

Recent Examples on the Web

Brunet’s laboratory has spent years developing a model for aging using African turquoise killifish. — Panashe Matemba-Mutasa, Mercury News, 5 Aug. 2026

For the first time in 10 years, researchers have discovered a new species of Xenurolebias killifish from an isolated swamp about 2 feet deep in eastern Brazil. — Lauren Liebhaber september 23, Miami Herald, 23 Sep. 2025

In his own research, Whitehead has shown that Atlantic killifish, a small silvery fish found off eastern Canada and the United States, has adapted to live comfortably in estuaries plagued by heavy industrial pollution. — Brian Owens, Smithsonian Magazine, 26 Jan. 2024

Word History

Etymology

killie killifish (perhaps from kill entry 3) + fish

First Known Use

1836, in the meaning defined at sense 1