What is Yeah, Right!?
1.
A reply to someone saying sarcastically, "Yeah, right." Instead of getting defensive, this remark is doubally sarcastic. If somebody's being stuck up and thinks they're cool by being sarcastic, saying this will make them reallly mad because they know they've been defeated.
Aimee: Guess what?
Brianna: Chicken butt. No, I lied. What?
Aimee: My basketball team just won the high school championships!
Brianna: Yeah right. (sarcastically)
Aimee: Yeah, right! (enthusiastically) I'm so glad you understand!
See
2.
Ironic or sarcastic expression of agreement that really means disagreement or dismissal. See
No, Howard Dean is a man of character and conviction . . .
Yeah, right!