a small motorcycle designed and built with special tires and suspension for riding on unpaved roads and over rough terrain.
Origin of trail bike
First recorded in 1965–70
Also called dirt bike.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for dirt bike
a motorcycle adapted for riding on rough tracks
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012