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.
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.
a. Capable of firing continuously until ammunition is exhausted or the trigger is released: an automatic rifle.
b. Semiautomatic: an automatic pistol.
1. An automatic machine or device.
a. An automatic firearm.
b. A semiautomatic firearm.
3. A transmission or a motor vehicle with an automatic gear-shifting mechanism.
4. Football See audible.
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·ma·tici·ty (-mə-tĭsĭ-tē) n.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.