bˈʌmpɪŋ ɪz wɛn ðə tɹænsmˈɪʃən ɹᵻlˈiːsᵻz ˈɔːl ðə pɹˈɛʃɚɹ ɔnðə ɹᵻvˈɜːs ɡˈɪɹ fɚɹə spˈɛsᵻfˌaɪd ɐmˈaʊnt ʌv tˈaɪm, ɐlˈaʊɪŋ ðə kˈɑːɹ tuː "bˈʌmp" fˈɔːɹwɚd.
Bumping is when the transmission releases all the pressure on the reverse gear for a specified amount of time, allowing the car to "bump" forward.