1919, "of or having to do with sound waves beyond the limit of human hearing," from super- + sonic. Attested from 1934 in sense of "exceeding the speed of sound" (especially as a m [..]

faster than the speed of sound, 343 meters per second (1,125 feet per second).

Velocity greater than the speed of sound. The SR-71 is characterized as a supersonic aircraft because it travels from three to four times the speed of sound. A supersonic aircraft can fly from New York to ?London in less than two hours.

(context, of a sound) having a frequency too high to be audible (context, of a speed) greater than the speed of sound (in the same medium, and at the same temperature and pressure)

(adj) (of speed) greater than the speed of sound in a given medium (especially air)(adj) having frequencies above those of audible sound

Speed of flight at or greater than Mach 1.0; literally, faster than the speed of sound.

Faster than sound. Formerly this term was also applied to a frequency above the audible range, but in this usage it has been replaced by the term ULTRASONIC.

Speed in excess of that of sound.

(of a speed) greater than the speed of sound (in the same medium, and at the same temperature and pressure) (colloquial,of a sound) ultrasonic, having a frequency too high to be audible