Doctor Who TARDIS Acronym T Shirt This Doctor Who t shirt is a guaranteed conversation starter, as you explain the scientific concept behind Doctor Who?s TARDIS time machine. The Doctor Who TARDIS Acronym T Shirt features the meaning of TARDIS, ?Time and Relative Dimension in Space,? in white letters on a Navy blue background. Adding to the fun, the words are formed in the shape of a TARDIS as well..