Clockwork

Clockwork was the inner workings of a clock or any similar, mechanical device. It was usually powered by a winding or self-winding device that, when wound, generated energy through a spring, pendulum or gear to create a motion. Wind-up toys frequently contained clockwork.

During his travels, the Doctor encountered various types of clockwork robots. (TV: The Mind Robber, The Girl in the Fireplace, Deep Breath, Heaven Sent; PROSE: The Clockwise Man) He also created his own clockwork robots. (TV: Under the Lake, Before the Flood; PROSE: Model Train Set)

The Moment was apparently clockwork. (TV: The Day of the Doctor)