Whoo! Share definition Flag What is said when one has something amazing or scary happen to them. PETROL BOMB EXPLODES: "Whoo!" FALLS OFF LADDER: "Whoo! <CRACK> Oww!" (Eh hehe) Whoo! by Marko Ballantyne August 7, 2004 0 0 Get merch Get the Whoo! mug. Buy Now — $32.95 See more merch