speed

(noun) distance travelled per unit time. Synonyms: velocity.

(noun) a rate (usually rapid) at which something happens. Synonyms: swiftness, fastness. Examples: "The project advanced with gratifying speed."

(noun) changing location rapidly. Synonyms: speeding, hurrying.

(noun) the ratio of the focal length to the diameter of a (camera) lens system. Synonyms: focal ratio, f number, stop number.

(noun) a central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression. Synonyms: amphetamine, pep pill, upper.

(verb) move fast. Synonyms: rush, hotfoot, hasten, hie, race, pelt along, rush along, cannonball along, bucket along, belt along, step on it. Examples: "He rushed down the hall to receive his guests." "The cars raced down the street."

(verb) move faster. Synonyms: accelerate, speed up, quicken. Examples: "The car accelerated."

(verb) move very fast. Synonyms: travel rapidly, hurry, zip. Examples: "The runner zipped past us at breakneck speed."

(verb) travel at an excessive or illegal velocity. Examples: "I got a ticket for speeding."

(verb) cause to move faster. Synonyms: accelerate, speed up. Examples: "He accelerated the car."