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1.
A unit of measurement similar to a man-hour, but taking place in Las Vegas and involving more hookers.

Note: Rainman-Evenings are typically used to measure how to divide a hotel room's cost amongst several people:
"All right, so Tom, Paul, Jim, and Ben are going to be staying in the DaddySuite for 3 nights, Mike for 2 nights, and "the Bone" is in for 1 night... that brings us a grand total of 15 Rainman-Evenings... Ben, you figure out how much per night that is, now who is next on the hooker?"
by tBCSeattle1 February 27, 2009