|(not in technical usage) sonic barrier, Also called: transonic barrier a hypothetical barrier to flight at or above the speed of sound, when a sudden large increase in drag occurs|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
|a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.|
The sharp increase in drag experienced by aircraft approaching the speed of sound. Also called sonic barrier.
The sudden increase in air resistance that occurs when an aircraft approaches the speed of sound. This is also called the sonic barrier.