A time/space machine concieved by the Time Lords. It has infinate rooms inside, including several console rooms, from which the ship can be piloted. Doctor Who stole a mark 40 TARDIS and used it to solve intergalactic wrong-doings.
With the TARDIS The Doctor can travel to any point in time and space.
The inside of the TARDIS is larger then the outside.
The TARDIS used to have the ability to disguise itself according to its environment around it, but in 1963 when it landed in London it became “stuck” in the form of a police box. The Doctor has given up trying to fix it, because he has grown fond of the police box shape.
Also the vessel’s navigation system is old and unreliable, which is why The Doctor explores the universe at random.
"Its the TARDIS, it's my ship"
When you enter a TARDIS you are steping out of your reality and into another through the dimentional tear in space.
The TARDIS, Its bigger on the inside.
2) A woman who sleeps around; who is "Bigger on the inside than on the outside"
"Awh man! I regret sleeping with Jenny, last night! She's such a Tardis!"