To vomit as a result of excessive drinking, motion sickness, or a flu. Basically, to crap from the mouth.
Pull over, I think I'm going to drop a mouth deuce.

I should not have had those last few drinks. When I got home, I mouth deuced all over my living room.

I'm not going to be in today, I've been dropping mouth deuces all night.
by ADKat8 June 27, 2010
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