swordtail

[sawrd-teyl, sohrd-]
noun
  1. any of several small, brightly colored, viviparous, freshwater fishes of the genus Xiphophorus, native to Central America, having the lower part of the caudal fin elongated into a swordlike structure: often kept in aquariums.

Origin of swordtail

First recorded in 1925–30; sword + tail1
Also called helleri.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for swordtail

swordtail

noun
  1. any of several small freshwater cyprinodont fishes of the genus Xiphophorus, esp X. helleri, of Central America, having a long swordlike tail
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012