(esp. of liquor, computer software, or recordings) made, distributed, or sold illegally : bootleg cassettes | bootleg whiskey. verb ( -legged, -legging) [ trans. ] make, distribute, or sell (illicit goods, esp. liquor, computer software, or recordings) illegally : [as n. ] ( bootlegging) domestic bootlegging was almost impossible to control | [as adj. ] ( bootlegged) bootlegged videos. 1 [ intrans. ] (of a moving object) collide violently with an obstacle or another moving object : the coffin slipped out the back door, slid down the hill, and crashed. • [ trans. ] cause (a moving object) to collide in this way. • (of an aircraft) fall from the sky and violently hit the land or sea : a jet crashed 200 yards from the school. • [ trans. ] cause (an aircraft) to fall from the sky in this way. • informal (of a business, a market, or a price) fall suddenly and disastrously in value : silver prices crashed in early 1980. • Computing [ intrans. ] (of a machine, system, or software) fail suddenly : the project was postponed because the computer crashed. • informal [ intrans. ] go to sleep, esp. suddenly or in an improvised setting : I'll crash in the back of the van for a couple of hours. 2 [ intrans. ] move with force, speed, and sudden loud noise : huge waves crashed down on us. • [ trans. ] move (something) in this way : she crashed down the telephone receiver. • make a sudden loud, deep noise : the thunder crashed.