What is putain?

It seems like you might be referring to "Putain" which is a French colloquial term. "Putain" is a slang word in French that is often used as an expletive or to express surprise, frustration, or emphasis. It can be roughly translated to "damn" or more vulgar equivalents in English, depending on the context. It is derived from the word for "prostitute," but in modern usage, it's commonly used in various informal contexts among French speakers. While it's prevalent in everyday language, it's considered vulgar and should be used with caution, particularly in polite or formal settings.