Fustian is a noun that refers to pompous or pretentious speech or writing.
Coming from the Latin word fustaneum (foo STAN ee oom) which refers to a specific kind of cloth, our word of the day’s meaning has shifted over time to now refer to speech or writing that is thought of as pompous or pretentious. Example:
At the time, I was impressed by the professor’s speech as a student. But looking back, I now recognize his words as pure fustian.