Nine-to-five activity is a term used to describe a JOB that requires a person to work from 9am to 5pm, usually Monday through Friday. It is a type of JOB that is considered to be a regular, full-time JOB with a set schedule and hours. The term is often used to refer to office jobs, but it can also refer to any JOB that requires a person to work during those hours. The three letter solution for this crossword is JOB.