automatic

1. (of a firearm such as a machine gun) Firing continuously as long as the trigger is pressed until ammunition is exhausted.Examples: "Fully automatic weapons cannot be legally owned by private citizens in the US, except in very special circumstances, as by private security companies."

2. (of a handgun) An autoloader; a semi-automatic or self-loading pistol, as opposed to a revolver or other manually actuated handgun, which fires one shot per pull of the trigger; distinct from machine guns.Examples: "The US Army adopted John Browning's M1911 pistol as its sidearm, chambered in .45 ACP (Automatic Colt Pistol)."; "From a little hand-bag he extracted his automatic pistol, which he put upon the mantelpiece."

3. (programming, of a local variable) Automatically added to and removed from the stack during the course of function calls.Examples: "Automatic variables are created on the stack. They are valid only from the point where they are declared to the end of the function."

4. (mathematics, of a group) Having one or more finite-state automata.