A word used in Wisconsin, Michigan and surrounding areas that translates to "Yes," or, "Yes, I agree." It is similar to "ya know hey."
Yaderhey is thought to be the opposite of a phrase derived from Bob and Doug McKenzie in the movie Stange Brew, "No way, eh." You would then replay, "Yaderhey."
Bob: Hey man, that was a hotchicky last night at the ho-down, eh?
Yader is the type of person to ignore your cry for help. Instead a Yader will continue to do whatever he is doing. A Yader usually doesn't have remorse for anyone and will go a long for whatever makes other people laugh because he's so empty on the inside.
P1: Wow that guy looks exactly like a Yader
P2: I know right? Look at him.