Definition & Meaning of "(pardon|excuse) {one's} (French|language)"

What is the origin of the idiom "pardon one's French" and when to use it?

The origin of the idiom "pardon one's French" is believed to date back to the 19th century. During this time, French was often associated with elegance and sophistication. When people wanted to use strong or offensive language, they might have jokingly used the phrase "pardon my French" as a way to apologize for using words that were considered impolite. It is now used humorously to acknowledge the use of inappropriate language, with "French" serving as a metaphor for such language.