Best definition
Short-hand for “Yeah, Yeah, Woo!”, an exclamation conferring the feeling of excitement while, at the same time, ending a conversation.

Typically used to terminally punctuate just about any tele-mobile-phone text or electronic chat.

Praise the lord, we’re finally done with that dreaded renal pathophysiology exam tomorrow. Whew! I am really excited for getting completely obliterated afterwards. Alright sucka, G-chat you later! YYW!
YYW!: define #2
‘Yeah yeah whatever’. A way to dismiss someone or something which is boring. Originated on the net. Said: ‘Why Why Woo’.
‘OMG did you see those pictures of Avril Lavigne looking like a skanky little ho bag?’

‘yyw, Avrils so summer ’04’