automatic

Adjective

• without volition or conscious control
  • the automatic shrinking of the pupils of the eye in strong light
    
  • a reflex knee jerk
    
  • sneezing is reflexive
    

• resembling the unthinking functioning of a machine
  • an automatic `thank you'
    
  • machinelike efficiency
    

• operating with minimal human intervention; independent of external control
  • automatic transmission
    
  • a budget deficit that caused automatic spending cuts
    

Noun

• a pistol that will keep firing until the ammunition is gone or the trigger is released

• light machine gun

Related words

• Synonyms: 
  reflex(a) , reflexive , automatonlike , machinelike , robotlike , robotic , automatic pistol , automatic rifle , machine rifle