Tabarnack

Tabarnack is one of the strongest swearing word in french. It comes from "tabernacle" which was a word used in churches back when Quebec was Catholic.
The definition varies:
it can be used as an adjective meaning "a lot"
it can mean a simple swearing word such as "fuck, damnit"
it can be put in the middle of other swear to accentuate the anger

mon osti de tabarnack, ma te tuer!(Fucking asshole, i'll kill you)
tabarnack, t'étais où?(What the fuck, where were you?)
j'ai de l'argent en tabarnack!(I got a lot of money)
t'es belle en tabarnack! (You are incredibly pretty)