RC's gommil reminded me of another favourite which I now use all the time:

stunned: (adj) stupid (best pronounced with the Newfoundland-style u which sounds like the Liverpudlian u) Sample sentence: "B'y, are you too stunned to see that that's not gonna work?"

Note that b'y is THE classic Newfoundland word, equivalent to the Aussie mate and used to address someone (girl or boy!) or just for emphasis. That's one I can't ever sound natural saying.