automatic in WordNet English dictionary

1. light machine gun
   automatic rifle  automatic  machine rifle 
   
2. a pistol that will keep firing until the ammunition is gone or the trigger is released
   automatic pistol  automatic 
   

1. operating with minimal human intervention; independent of external control
   "automatic transmission"; "a budget deficit that caused automatic spending cuts"
   automatic 
   
2. without volition or conscious control
   "the automatic shrinking of the pupils of the eye in strong light"; "a reflex knee jerk"; "sneezing is reflexive"
   automatic  reflex  reflexive 
   
3. resembling the unthinking functioning of a machine
   "an automatic `thank you'"; "machinelike efficiency"
   automatic  automatonlike  machinelike  robotlike  robotic