Subsonic vs. Supersonic

Difference Between Subsonic and Supersonic
Subsonicadjective
(of a sound, scientific) having a frequency too low to be audible
Supersonicadjective
(of a speed) greater than the speed of sound (in the same medium, and at the same temperature and pressure)
Subsonicadjective
(of a sound, literary) very quiet, almost inaudible
The noise of the ship was all around her. The faint subsonic rumble of the reactor and drive. (Leviathan Wakes, James S. A. Corey)Supersonicadjective
ultrasonic, having a frequency too high to be audible
Subsonicadjective
(of a speed) (aviation) less than the speed of sound (in the same medium, and at the same temperature and pressure)
Supersonicnoun
An aircraft that can travel at the speed of sound.
Subsonicadjective
with a Mach number such that 0.3 < Ma < 0.8 (approximately - the exact limits vary between sources)
Supersonicadjective
(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 horizonaircraft flying at subsonic speedsSubsonicnoun
an aircraft whose maximum speed is less than the speed of sound
Supersonicadjective
having frequencies above those of audible sound
Subsonicadjective
(of speed) less than that of sound in a designated medium;
aircraft flying at subsonic speedsa supersonic bomber flies so fast that it must release its bombs while the target is still over the horizon