speed meaning and definition

SPEED noun

Definition of speed (noun)

1. distance travelled per unit time
   • synonyms: velocity
2. a rate (usually rapid) at which something happens
   • "the project advanced with gratifying speed"
   • synonyms: fastness, swiftness
3. changing location rapidly
   • synonyms: hurrying, speeding
4. the ratio of the focal length to the diameter of a (camera) lens system
   • synonyms: f number, focal ratio, stop number
5. 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

SPEED verb

Definition of speed (verb)

1. move fast
   • "He rushed down the hall to receive his guests"; "The cars raced down the street"
   • synonyms: belt along, bucket along, cannonball along, hasten, hie, hotfoot, pelt along, race, rush, rush along, step on it
   • antonym: dawdle
2. move faster
   • "The car accelerated"
   • synonyms: accelerate, quicken, speed up
   • antonym: decelerate
3. move very fast
   • "The runner zipped past us at breakneck speed"
   • synonyms: hurry, travel rapidly, zip
4. travel at an excessive or illegal velocity
   • "I got a ticket for speeding"
5. cause to move faster
   • "He accelerated the car"
   • synonyms: accelerate, speed up
   • antonym: decelerate