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.