Unc Share definition Flag A crazy, old black man. Uncs are usually senile or under the influence of crack cocaine. Sometimes both. There was an unc screaming at himself outside of Waffle House so I went to Golden Corral instead. Unc by Ichdkslwuueo82 April 29, 2024 0 0 Get merch Get the Unc mug. Buy Now — $32.95 See more merch