from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. See sonic barrier.
  • n. A set of tall wooden, plastic, or concrete barriers placed along a road or highway to muffle the sound of traffic.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The apparent physical boundary (caused by a sudden increase in drag) preventing objects from becoming supersonic.
  • n. A structure beside a highway designed to reduce the noise of traffic.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. the increase in aerodynamic drag as an airplane approaches the speed of sound


Sorry, no etymologies found.


  • X-1 program: accidents in, Armstrong as pilot in Bikle’s views about breaking of sound barrier by, and Crossfield ending of, Mach speeds on pilots in, range of, simulator for and techniques for maneuvering in outer space and Walker and Williams and program and Yeager

    First Man

  • The first time Armstrong broke the sound barrier came in October 1955, an F-100A flight investigation of longitudinal stability and control characteristics involving various wing slots and slats in different leading-edge configurations.

    First Man


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