lunge (l?nj)n.1. A sudden thrust or pass, as with a sword.2. A sudden forward movement or plunge.v. lunged, lung·ing, lung·es v.intr.1. To make a sudden thrust or pass.2. To move with a sudden thrust.v.tr. To cause (someone) to lunge.[From alteration of obsolete allonge, to thrust, from French allonger, from Old French alongier, to lengthen : a-, to (from Latin ad-; see ad-) + long, long (from Latin longus; see del- in Indo-European roots).]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.