Distance travelled per unit time WordNet 3.0 & Open English WordNet

Velocity is the speed in combination with the direction of motion of an object. Wikipedia

Quantity in physics that is related to speed. Wikipedia Disambiguation

A scalar measure of the rate of movement of a body expressed either as the distance travelled divided by the time taken (average speed) or the rate of change of position with respect to time at a particular point (instantaneous speed). It is measured in metres per second, miles per hour, etc. OmegaWiki

The rate of motion or action, specifically (mathematics)/(physics) the magnitude of the velocity; the rate distance is traversed in a given time. Wiktionary

Rate of motion. Wiktionary (translation)

A vector quantity that denotes the rate of change of position with respect to time, or a speed with the directional component. Wiktionary

Vector quantity. Wiktionary (translation)