Greater than the speed of sound (in the same medium, and at the same temperature and pressure).
Ultrasonic, having a frequency too high to be audible.
An aircraft that can travel at the speed of sound.
Fast; quick; rapid.
Capable of moving at high speeds.
Any of various fast-flying hesperiid butterflies.
A moth of the family Hepialidae, swift moth, ghost moth.
A small plain-colored bird of the family Apodidae that resembles a swallow and is noted for its rapid flight.
A light, collapsible reel used to hold a hank of yarn in order to wind off skeins or balls.
The main cylinder of a carding-machine.
Any of certain lizards of the genus Sceloporus.