ro·nin (r??n?n)n. pl. ronin or ro·nins A samurai who is not in the service of a feudal lord.[Japanese r?nin, from Early Middle Chinese la?` ?in, vagabond (also the source of Mandarin l`ngrén) : la?`, a wave, reckless, dissolute + ?in, person.]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.ronin (?r??n?n) n1. (Historical Terms) a lordless samurai, esp one whose feudal lord had been deprived of his territory2. (Government, Politics & Diplomacy) a lordless samurai, esp one whose feudal lord had been deprived of his territory3. (Historical Terms) such samurai collectively4. (Government, Politics & Diplomacy) such samurai collectively[Japanese]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014