Tabarnaque is an obscene/blasphemous exclamation used in Quebec, Canada. It is one of those slang terms that has no complete translation. From what I've been able to dig up it means roughly God damn it!, but from how people react if you use it in polite company, it seems to be much stronger. Can also be shortened to tabernak. For more background information see Cursing in French and French slang. See also Tabernacle.