WordNet sense 1 (light machine gun):

automatic rifle, machine rifle

WordNet sense 2 (a pistol that will keep firing until the ammunition is gone or the trigger is released):

automatic pistol

WordNet sense 3 (without volition or conscious control):

reflex, reflexive, reflex

WordNet sense 4 (controlled by the autonomic nervous system; without conscious control):

involuntary

WordNet sense 5 (like the unthinking functioning of a machine):

automatonlike, machinelike, robotlike

WordNet sense 6 (using (or as if using) mechanisms or tools or devices):

mechanical

WordNet sense 7 (designed to activate or move or regulate itself):

self-regulating, self-acting, self-moving