A self-operating machine or mechanism, especially a robot.(noun)
One that behaves or responds in a mechanical way.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "automaton" in a sentence
"The automaton is all that is left of his previous life."
"The automaton is one of many built to help Lincoln hit the campaign trail and who subsequently became the sheriff of a small town."
"This year’s homework question was to find an interesting cellular automaton from the rule space of radius 3/2 with two colors."