automaton

noun (plural automata /-tə/ or automatons)

• a moving mechanical device made in imitation of a human being.
• a machine that performs a function according to a predetermined set of coded instructions, especially one capable of a range of programmed responses to different circumstances.
• used in similes and comparisons to refer to a person who seems to act in a mechanical or unemotional way:she went about her preparations like an automaton