This means hugs and kisses now in the same way that LOL could have ended up Lots Of Love instead of Laugh Out Loud. Language is an interesting thing, i'ts forever evolving. Purse your lips. Ok it looks like "X". Thats the kiss. Blow it. "O", thats the shape. Its a blown kiss, that's all. See: Mwah Mwah. The definition: Hugs and kisses, because: that's what everyone thinks it means when they use it.