From Wiktionary, the free dictionary
From Uranus, which may be confused with your anus; preserving the original joke, as Urectum may be confused with the synonymous your rectum.
Possibly introduced in "A Big Piece of Garbage" (1999), season 1, episode 8 of Futurama.
Urectum
- (humorous) Uranus (a gas giant, the 7th planet of the Solar System)
2004 April 8, Barry Posner, “Re: 2000 tony stewart 1/24 diecast..”, in rec.autos.sport.nascar[1] (Usenet), message-ID <4075B9D3.F9910505@psu.edu>:> hell if you'll pay,
>
> I may even ship to Uranus.
What about Urectum?
