speed

Noun

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

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

• changing location rapidly

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

• distance travelled per unit time

Verb

• cause to move faster
  • He accelerated the car
    

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

• move very fast
  • The runner zipped past us at breakneck speed
    

• move faster
  • The car accelerated
    

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

Related words

• Synonyms: 
  amphetamine , pep pill , upper , focal ratio , f number , stop number , speeding , hurrying , swiftness , fastness , velocity , accelerate , speed up , travel rapidly , hurry , zip , quicken
• Antonyms: 
  decelerate , slow down , slow , slow up , retard