yo /jəʊ $ joʊ/
interjection especially American English informal[
Date: 1400-1500;
Origin: A natural form of greeting]
used to greet someone, to get their attention, or as a reply when someone says your name:
Yo, dude! How’s it going? ‘Darren?’ ‘Yo!’ [TahlilGaran] Dictionary of Contemporary English ▲