woo Share definition Flag it is the result of poo and wee combined. Because One does not expell poo solely, the product in the toilet basin is often "woo". "Hey man, I need to go to the toilet." "number 1 or number 2?" "Both man..I'm talking about woo" woo by Shaun. August 19, 2003 0 0 Get merch Get the woo mug. Buy Now — $32.95 See more merch