speed

distance travelled per unit time

a rate (usually rapid) at which something happens; "the project advanced with gratifying speed"

changing location rapidly

the ratio of the focal length to the diameter of a (camera) lens system

a central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression

move fast; "He rushed down the hall to receive his guests"; "The cars raced down the street"

move faster; "The car accelerated"

move very fast; "The runner zipped past us at breakneck speed"

travel at an excessive or illegal velocity; "I got a ticket for speeding"

cause to move faster; "He accelerated the car"