A verb in which the past tense is not formed by adding the usual -ed ending. Examples of irregular verbs are sing (past tense sang); feel (felt); and go (went). (Compare regular verb.)

The New Dictionary of Cultural Literacy, Third Edition Edited by E.D. Hirsch, Jr., Joseph F. Kett, and James Trefil. Copyright © 2002 by Houghton Mifflin Company. Published by Houghton Mifflin. All rights reserved.