When someone try's to say something funny or tell a joke and its not funny at all or no one laughs. you say O.Z. also you can say O.Z. to make someone mad even if they did not try to tell a joke.
Originated in TRUMBULL CONNECTICUT in Joey D's beach house with Robert Ryan Niko Principi Thomas Nolan and Luke Pearson after watching the rap battle O.Z. Vs. jack shit. the rapper O.Z. was doing a poor job at trying to rap and joke, so ever since that anything that isn't funny is now considered an O.Z.
Thomas " Her boobs are so nice. You get the left one i get the right one BOOOM...haha"
joey - "o.z."