lung·fish (l?ng?f?sh?)n. pl. lungfish or lung·fish·es Any of several freshwater lobe-finned fishes of the group Dipnoi of Africa, South America, and Australia, having a lunglike organ that enables them to breathe air, especially during drought conditions.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.lungfish (?l???f??) n, pl -fish or -fishes (Animals) any freshwater bony fish of the subclass Dipnoi, having an air-breathing lung, fleshy paired fins, and an elongated body. The only living species are those of the genera Lepidosiren of South America, Protopterus of Africa, and Neoceratodus of AustraliaCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014lung?fish (?l???f??) n., pl. (esp. collectively) -fish, (esp. for kinds or species) -fish?es. any fleshy-finned fish, related to the ancient crossopterygians, having lungs as well as gills, including three surviving genera: Neoceratodus of Australia, Protopterus of Africa, and Lepidosiren of South America. [1880?85] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.lung·fish (l?ng?f?sh?) Any of several tropical freshwater fish that, in addition to having gills, have lung-like organs for breathing air. Lungfish have a long, narrow body, and certain species can survive periods of drought inside a mucus-lined cocoon in the mud. The lungfish and the coelacanths are the only living lobe-finned fishes.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.