{v. phr.} 1. To push down on the gas pedal to make a car go faster. * /Be very careful when you step on the gas. Don't go too fast./ Compare: GIVE IT THE GUN. 2. {informal} To go faster; hurry. * /Step on it, or we'll be late for school./ * /John is a slow starter, but he can step on the gas when it looks as if he might lose the race./ * /Lee was wasting time at breakfast and his father told him to step on it or they would miss the bus./
See: STEP ON IT.