<p><strong>Adjective</strong></p><ul><li>Having the capability of starting, operating, moving, etc., independently: an automatic sprinkler system; an automatic car wash.</li><li>Physiology: occurring independently of volition, as certain muscular actions; involuntary.</li><li>Done unconsciously or from force of habit; mechanical: an automatic application of the brakes.</li><li>Occurring spontaneously: automatic enthusiasm.</li><li>(Of a firearm, pistol, etc.) Utilizing the recoil or part of the force of the explosive to eject the spent cartridge shell, introduce a new cartridge, cock the arm, and fire it repeatedly.</li></ul><p><strong>Noun</strong></p><ul><li>A machine that operates automatically.</li><li>Automatic rifle.</li><li>Automatic pistol.</li><li>Football: audible (def 2).</li><li>Automatic pilot.</li><li>Automatic transmission.</li><li>An automobile equipped with automatic transmission.</li></ul>