WWordGenerator.org GeneratorsWord ListsBlogAboutGenerate a word Home / S / sound barrier sound barrier noun /saʊndbæriər/ 3 syllables 13 letters Scrabble 15 WWF 18 Definitions noun the increase in aerodynamic drag as an airplane approaches the speed of sound sonic barrier Look “sound barrier” up elsewhere Wiktionary ↗ Merriam-Webster ↗ Etymonline ↗ Dictionary.com ↗ Want another word?Spin the dictionary for a fresh one. Generate a word →