What does it mean that a domain has "legs"?

[TordB.com]

What does it mean that a domain has "legs"? By the way English is not my first language. Here is the blogpost where Eric talked about a domain having legs:

http://www.ricklatona.com/2008/05/14/what-makes-a-domain-sellable-part-3/http://www.ricklatona.com/2008/05/14/what-makes-a-domain-sellable-part-3/

 

[nielsencl]

That question is answered in the post:

It means that when your site is up and running, it’ll keep on running further and further. It implies that it can continue to get bigger and more profitable as time goes on.

 

[tyggemannen]

A domain with a good future has legs Do you have one?