A noise made to sexy girls to gain there attention and hopefully pull them.
Often used by the manchesterians of britain.
Another way of doing the 'Wolf whistle'.
For 100% pulling action 'Whit woo' must partially be spoken through the nose creating a kind of hum.
A troubled manchesterian "Whit woo, sexy pants. Wanna come set some dustbins on fire and sniff the fumes?"