Adjective

1. supersonic (vs. sonic) (vs. subsonic)

usage: (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"

2. supersonic, ultrasonic, inaudible (vs. audible), unhearable

usage: having frequencies above those of audible sound

See also: supersonic (Dictionary)