Popular use of the word Whovian is thought to originate from the Doctor Who Fan Club of America, who formerly produced a newsletter entitled The Whovian Times. Unlike the term Trekkie, which appears in the Compact Oxford English Dictionary as ’a fan of the US science-fiction programme Star Trek’, Whovian has yet to be formally recorded as an English word. However the word for the Doctor’s time travelling machine, Tardis (an acronym of Time And Relative Dimensions In Space, externally a small police telephone box, but internally a time travel base of generous proportions) has gained general currency as an informal description of ‘an unexpectedly large space’, and is defined in the Encarta® World English Dictionary as ‘a room or building that seems to be much larger than it actually is or appears to be from the outside.’