The crossword solution for the term 'Believe it or Not!' is NOT, which is a three-letter word. This phrase is often used to express disbelief or surprise at something that has been said or done. It is usually followed by an exclamation mark to emphasize the speaker's disbelief. The phrase is often associated with the American show of the same name, which was hosted by Robert Ripley and featured stories of unusual people, places, and events.