Tight Do is a hairstyle that was popularized in the 1950s. It is characterized by a very short, close-cropped cut with a high fade. The term 'tight do' comes from the fact that the hair is cut so close to the scalp that it appears to be tight against the head. The crossword solution BUN refers to the BUN that is often worn on the back of the head with this style. This BUN is usually made up of the remaining hair after the tight do has been cut.