Jumping the gun is an idiom that means to act too quickly or without proper thought or preparation. It can be used to describe a situation where someone has acted too soon, often with negative consequences. The crossword solutions for this term are RASH (4 letters), EARLY (5 letters), and PREMATURE (9 letters). RASH implies acting without thinking, EARLY suggests acting before the appropriate time, and PREMATURE implies acting before something is ready.