Definition of "topminnow" [topminnow]

• Any of several small New World freshwater fishes of the genus Fundulus, related to the killifishes. (noun)
• Any of various small viviparous New World fishes of the family Poeciliidae, of fresh or brackish waters. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In a separate concern, the feds are taking a look at the Gulf's now-scarce, saltmarsh topminnow."
• "Jones said one of the advantages to protecting topminnow habitat now is that marsh building offers protection against storms for people living further inland."
• "The Barrens topminnow was first discovered in 1983 in a handful of locations in middle Tennessee."