rock bass (b?s)n. A freshwater food and game fish (Ambloplites rupestris) of eastern and central North America, chiefly found in streams and rivers with rocky bottoms.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.rock bass (bæs) n1. (Animals) a North American freshwater percoid fish, Ambloplites rupestris: an important food fish; family Centrarchidae (sunfishes, etc)2. (Animals) any similar or related fishCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014rock? bass` (bæs) n. 1. a sunfish, Ambloplites rupestris, of the Mississippi basin. 2. striped bass. [1805?15, Amer.] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.