(from Merriam-Webster Dictionary, New Edition, copywright 2005): YO- "used to call attention, indicate attentiveness, or express affirmation".
Ah... That's the definition, but what is the 'meaning'? That's the question. Sort of 'Why is there air?' Answer-to blow up basketballs, of course. Yo? HERM
It would appear in this case that if we say "Why do people say YO?"(in reference to your air question) Doc Webster provides the answer in his definition. Or, are you looking for the ORIGIN of the word ?
Oh my you're taking this way to literally. I'm speaking of the existential meaning of 'yo', that which lamas on high mountain tops have meditated to for centuries. They're not saying "Ommmmm", they're saying "Yooooom". HERM
