noun
definition
An aircraft whose maximum speed is less than the speed of sound
adjective
definition
(of a sound, scientific) having a frequency too low to be audible
definition
(of a sound, literary) very quiet, almost inaudible
example
The noise of the ship was all around her. The faint subsonic rumble of the reactor and drive. (Leviathan Wakes, James S. A. Corey)
definition
(of a speed) less than the speed of sound (in the same medium, and at the same temperature and pressure)
definition
(of a flow) with a Mach number such that 0.3 < Ma < 0.8 (approximately - the exact limits vary between sources)
Examples of subsonic in a Sentence
The barrel was short and the bullet emerged at subsonic speed.
Subsonic aircraft have been measured at twice the legal noise level, struggling to take off with heavy loads in adverse conditions.
The method is applicable for subsonic flight speeds when the flow over the aircraft is wholly subsonic and fully attached.
At the same time there were 1,941 infringements by subsonic jets.
It is concluded that the present method is accurate for quantitative predictions of unsteady heat transfer in subsonic turbine flows.
A pinch of the proper powder pushes this bullet out the muzzle at subsonic velocities, thus permitting silent fire.
Racks are subsonic filters and should really be thought of as an essential component in any Stereo or Home Cinema system.
With operating costs per passenger of 3.5 times that of a subsonic jet it was never going to be mass transport.