It is a way of saying hi and if your called Addison you probably say it a lot
A cantonese substitute for curse words.
"YO! I lost in the battle again!"
"Gosh, you are so YO stupid"
8 yo me was as exited for Diwali as I'm today exited for Jack Ryan 2.0
Yo how long does it take for you to verify my definition?!
Yo WTF?!