The feeling that you get, typically at the halftime of a football game, after you've been drunk during the day but it has started to wear off. Symptoms include mild headache, watery-mouth, and the insatiable desire to obtain more booze to prevent full-on sobriety.
"Dude...we need to find some more beer around here somewhere, I'm startin' to feel a Halftime Hangover sinking in"