rapidity of motion or operation; swiftness; speed

a high wind velocity.

Mechanics . the time rate of change of position of a body in a specified direction.

the rate of speed with which something happens; rapidity of action or reaction.

noun

acceleration , celerity , dispatch , expedition , fleetness , gait , haste , headway , hurry , impetus , momentum , pace , quickness , rapidity , rapidness , rate , swiftness , temponotes:speed is the distance an object travels during a unit of time; velocity is the distance an object travels in a specified direction during a unit of time , tempo , motion , speed