2. [syn: supersonic, ultrasonic]
The Collaborative International Dictionary of English v.0.48:
supersonic \su`per*son"ic\, a.
1. Moving at a speed greater than the speed of sound in air;
-- this speed varies with altitude, since the speed of
sound varies with altitude, as well as with temperature
and humidity, being approximately 1129 feet per second at
sea level and 984 feet per second at 16 miles altitude.
2. Capable of moving at speeds higher than the speed of
sound; -- of aircraft.
WordNet (r) 3.0 (2006):
adj 1: (of speed) greater than the speed of sound in a given
medium (especially air); "a supersonic bomber flies so
fast that it must release its bombs while the target is
still over the horizon" [ant: sonic, subsonic,
2: having frequencies above those of audible sound [syn: