Mechanical man (5)
I believe the answer is:
robot
'mechanical man' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for robot that I've seen before include "Mechanical man" , "Programmed machine" , "Lifelike machine" , "Automaton or sci-fi creature" , "Mechanism that can move like a human" .)