- Speed - Quickness of motion; swiftness; speed; celerity;
rapidity; as, the velocity of wind; the velocity of a planet or comet
in its orbit or course; the velocity of a cannon ball; the velocity of
light. - Rate of motion; the relation of motion to time, measured
by the number of units of space passed over by a moving body or point
in a unit of time, usually the number of feet passed over in a second.
See the Note under Speed.