sound barrier

American

noun

Also called transonic barrier. Also called sonic barrier. (not in technical use) a hypothetical barrier to flight beyond the speed of sound, so postulated because aircraft undergo an abruptly increasing drag force induced by compression of the surrounding air when traveling near the speed of sound.

idioms

break the sound barrier, to travel faster than the speed of sound.

sound barrier British

noun

Also called: sonic barrier. transonic barrier. (not in technical usage) a hypothetical barrier to flight at or above the speed of sound, when a sudden large increase in drag occurs

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of sound barrier

First recorded in 1950–55

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

sound barrier

"Even during our religious holidays, even on Good Friday, jets fly over us and break the sound barrier just to scare us," al-Jamal said.

From Barron's ● Apr. 5, 2026

The test flight of a plane called XB-1, developed by the company Boom Supersonic, became the first civilian jet to break the sound barrier since the Concorde.

From The Wall Street Journal ● Nov. 19, 2025

He set a record for fastest free fall, descending 127,852 feet at 843.6 mph and becoming the first human to break the sound barrier without the assistance of a vehicle.

From Los Angeles Times ● Jul. 18, 2025

Intense sonic booms could be heard overhead as Israeli jets broke the sound barrier.

From BBC ● Oct. 13, 2024

She not only got to fly the jet—she broke the sound barrier in it.

From "Women in Space" by Karen Bush Gibson

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023