Oh-yeah Definition

interjection

(informal, slang) Used to indicate agreement, often sarcastically.

Are you going to the party?Oh, yeah!
Wiktionary

(informal, slang) Used to introduce a refutation, sometimes sarcastically.

(In a poker game): I raise you twenty.Oh yeah? I think you're bluffing — I call.
Wiktionary

(informal, slang) An exclamation of excitement or joy.

Oh yeah, I got a new video game!
Wiktionary