Tabernac, (alternately tabernak or tabernaque) is a Quebec french swear word. Its official meaning is "the place where the Eucharist is kept in a Roman Catholic church", (or sometimes "the crossbeam of a church".) This doesn't seem to make any sense as a swear word for an english person, but that's because english swears are all based on sex, defecation and other things the puritans didn't like. French swears are based on cursing elements of the Catholic church.

Tabernac is an all-purpose swear that can be used in variable strengths. For instance "tabernac, c'est Montréal!" means "hot damn, it's Montreal". On the other hand, just muttering "tabernac" is equivalent to saying "oh f***".