1 definition by amadhatter53

Where a usually slutty girl, often drunk, gives it up to a somewhat large number of guys, one after another after another. Metaphorically speaking, the girl is like a urinal, just instead of urine, the guys using her are relieving themselves a little differently.
Guy 1: We're running trains on these girls in the bedroom.
Guy 2: Can I get in on that?
by amadhatter53 October 11, 2005
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