Clockwork was the inner workings of a clock or any similar, mechanical device. It was usually powered by a winding device that, when wound, generated energy through a spring, pendulum or gear to create a motion. Wind-up toys frequently contained clockwork.
Clockwork soldiers were present in the Land of Fiction. (TV: The Mind Robber)
Shade Vassily used clockwork technology in the 20th century. (PROSE: The Clockwise Man)
Clockwork Droids were 51st century robots on the SS Madame de Pompadour, as well as on its sister ship, the SS Marie Antoinette. (TV: The Girl in the Fireplace, TV: Deep Breath)
The Seventh Doctor created miniature clockwork people for his model train set. (PROSE: Model Train Set)
Iris Wildthyme claimed to be a renegade from a race known as the Clockworks. In this case, the name referred to their rigid demeanour and role in keeping the multiverse orderly. (PROSE: The Blue Angel)
The Twelfth Doctor took apart his radio in the TARDIS to make a clockwork squirrel. (TV: Under the Lake) Whilst explaining the Bootstrap Paradox, the Doctor sat the clockwork squirrel on top of his amplifier. (TV: Before the Flood)