| adj. 1.  a.  Acting or operating in a manner essentially independent of external influence or control: an automatic light switch; a budget deficit that triggered automatic spending cuts. b.  Self-regulating: an automatic washing machine. 2.  a.  Acting or done without volition or conscious control; involuntary: automatic shrinking of the pupils of the eyes in strong light. b.  Acting or done as if by machine; mechanical: an automatic reply to a familiar question. 3.  a.  Capable of firing continuously until ammunition is exhausted or the trigger is released: an automatic rifle. b.  Semiautomatic: an automatic pistol. n.Idiom: 1.  An automatic machine or device. 2.  a.  An automatic firearm. b.  A semiautomatic firearm. 3.  A transmission or a motor vehicle with an automatic gear-shifting mechanism.  on automatic  Functioning by or as if by automatic machine or device. [From Greek automatos : auto-, auto- + -matos, willing; see  men-1 in the Appendix of Indo-European roots.] au′to·mati·cal·ly adv. au′to·ma·tici·ty (-mə-tĭsĭ-tē) n. | 
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