by the cliford December 07, 2006

a fish with lungs, this fish cant breathe underwater but breathes above water filling its lungs mounted in the tail fin
by Llama_galama August 23, 2019

A fish lung is somebody who is a fool and is very weak. you may call somebody a fish lung if they back out of a fight or can not do something that concerns physical action
by daniel clarke February 07, 2007
