When one is at a bar drinking pints and pints of heavenly beer and goes to the toilet to empty his bladder each time before the next pint.

The acronym FIFO is corporate jargon which stands for "First In First Out".
Drew: Hey, Were's Mike? Second half's about to start!
Paul: He's off for a beer FIFO.
*2 minutes later*
Mike: Whose round is it?
by kuwlij August 16, 2010
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