1. The act of snogging/sucking face so industriously that one runs the very real risk of interfering with the snoggee's uvula - the bit of the soft palate that hangs down at the back of the mouth. Often associated with spin the bottle and other such pursuits. Anywhere teenagers or drunken students are present should be considered an "at risk" zone.
2. Can also be used as a verb: to uvulate.
1. Sober student: "That is some serious uvulation going on over there. That guy's, like, performing major surgery on that chick's throat."
Half-cut student: "Yeah, sick dude! On the other hand, once I've seen this pitcher away I will find it strangely appealing to engage in such practices."
2. Horrified bystander 1: "I can't believe it! Uvulating in public before 2 in the afternoon!"
Horrified bystander 2: "Oh! The youth of today have far too much saliva and absolutely no discretion!"