[n] a pistol that will keep firing until the ammunition is gone or the trigger is released
[n] light machine gun
[adj] operating with minimal human intervention; independent of external control; "automatic transmission"; "a budget deficit that caused automatic spending cuts"
[adj] like the unthinking functioning of a machine; "an automatic `thank you'"; "machinelike efficiency"
[adj] (physiology) without volition or conscious control; "the automatic shrinking of the pupils of the eye in strong light"; "a reflex knee jerk"; "sneezing is reflexive"