rip·rap (r?p?r?p?)n.1. Piled broken stones used as a foundation or to stabilize an easily eroded bank or slope.2. An assemblage of such broken stones.tr.v. rip·rapped, rip·rap·ping, rip·raps 1. To construct a riprap in or on.2. To strengthen with a riprap.[Reduplication of rap.]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.rip?rap (?r?p?ræp) n. 1. a quantity of broken stone for foundations, revetments of embankments, etc. 2. a foundation or wall of stones thrown together irregularly. [1570?80; gradational reduplication of rap1] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.