Australian slang; it is "good on you" said quickly in an Australian accent. American counterpart is good for you.
Ozzie: I fucked Jill last night!
Yank: Well, your mom gave me a blowjob last night while riding a cumming unicorn to a strip club
Ozzie: G'donya!
Yank: Well, your mom gave me a blowjob last night while riding a cumming unicorn to a strip club
Ozzie: G'donya!
by MuntedMoose December 30, 2015