Verboten, which first appeared in English in 1916, is used to describe things that are forbidden according to a law or a highly regarded authority.

Why do Americans say verboten?

"Verboten" implies a little more than forbidden/prohibited - it carries the nuance of being forbidden/prohibited by unquestionable authority.

Can you use verboten in a sentence?

Verboten sentence example

Just approaching the subject was verboten . Especially verboten is the notion of listing on your invitation where you're registered. ... We mutually agreed the subject of our tests was verboten until we were able to get together again in three weeks hence.