Why is Calice a swear word?

Why “Chalice” is a Swear in Quebec

Like many other Québécois French curses, calice has its origins in Roman Catholic ritual—it’s the communion chalice. As the Economist noted last fall, Quebec has a particular history of “using religious objects as swear-words.” … (communion wafer), or Tabarnak!

What does Calice de Tabarnak mean?

anger Esti de câlice de tabarnak: Very strong expression of anger.

How do you swear in Quebec?

In its full glory, you might hear something like: “Osti de tabarnak de sacrament, de câlice de ciboire de criss de marde!” The expressions can take on different spellings, and are often pronounced slightly differently from the official words. All of them have the approximate weight of “fuck” in English.