A clock was an instrument for measuring time, sometimes utilising a clockwork mechanism.
Types of clock Edit
The appearance of a grandfather clock was assumed on at least three occasions by the Master's TARDIS (TV: The Deadly Assassin, The Keeper of Traken, PROSE: The Eight Doctors), although it is unclear as to whether it functioned like a real one when in this form.
Sarah Jane Smith received a scanner watch from the Tenth Doctor. (TV: The Sarah Jane Adventures) [disputed statement] [additional sources needed]Steven Taylor found the Monk's watch in 1066. (TV: The Time Meddler)