ˈsound ˌbarrier BrE AmE noun
the sound barrier the sudden increase in air pressure against a vehicle, especially an aircraft, when it is travelling near the speed of sound
break the sound barrier (=travel faster than the speed of sound)
ˈsound ˌbarrier BrE AmE noun
the sound barrier the sudden increase in air pressure against a vehicle, especially an aircraft, when it is travelling near the speed of sound
break the sound barrier (=travel faster than the speed of sound)
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012