The term 'It's a Go' is an expression used to indicate that something is ready to begin. It is often used in the context of a project or event that has been approved and is ready to start. The two crossword solutions for this term are YES (3 letters) and OKAY (4 letters). YES is a simple affirmative answer, while OKAY is a more enthusiastic agreement. Both words can be used to express approval and readiness to proceed.