The crossword solution for the term 'HEADS WILL ROLL!' is a four-letter word, 'ROLL'. This phrase is an idiom that means someone will be held accountable for their actions and suffer the consequences. It is often used as a warning to those who are considering doing something wrong or unethical. The phrase is also used to express anger or frustration when someone has done something wrong. In other words, it is a way of saying that someone will be punished for their misdeeds.