To mount a cycle (of the dirt bike or BMX variety, usually) and jump large gaps with the assistance of power provided through either the engine or one's legs and a ramp. Stunts of all sorts can be performed while in mid-air, much to the amusement of onlookers and sometimes dismemberment of the performer. Great fun when done correctly. See also BMX freestyle, insanity. Has been known to cause concussions or massive head trauma.