Uncle Joe is an unofficial nickname for former Vice President Joe Biden. It most likely stems from his relaxed, carefree demeanor which is sometimes considered to be a bit creepy. Kinda got that creepy uncle thing goin' on. His breath most likely smells like bourbon and skoal.

The cool uncle that will teach you how to spell your name with pee in the snow, take you out for ice cream before supper time, teach you about guns, will give you your first drink, or share a joint with you while giving you life advice

Farts done when you are peeing at the urinal

A combination of Uncle Tom and G.I. Joe, an Uncle Joe is any member of the military (active or veteran) who would sell out their fellow service members to support a person who slanders POW's and Gold Star families, advocates torture, gleefully threatens to abandon our allies, and shows blatant disregard for the Geneva Conventions.

The one uncle that gives away money and has a wierd obsesion with airplanes.

When you shit yourself on an airplane after drinking coffee and have to throw your underwear away.