What does TARDIS stand for?

TARDIS stands for “Time And Relative Dimension In Space.” The term names the Doctor’s time machine and spacecraft in Doctor Who, and the acronym was explained in the programme’s first story, “An Unearthly Child,” in 1963.

The Doctor’s TARDIS is a Type 40 time ship from the civilisation of the Time Lords. Although it can travel through time and space, its most famous feature is that its interior is much larger than its exterior. Its usual outside form is a blue British police box, produced by a malfunctioning chameleon circuit that failed to disguise it properly.

The word “Dimension” has also appeared in the plural as “Dimensions.” Both forms have been used in Doctor Who, but the singular wording is the standard formulation in many modern references and is the wording used by the Ninth Doctor in “Rose.” The stored answer therefore gives a fair canonical answer.

The TARDIS is not simply a spaceship. It is portrayed as a living, telepathic, dimensionally transcendental machine with a strong connection to its traveller. Its signature dematerialisation sound was created at the BBC Radiophonic Workshop.