rookie
n. countablen. someone who is new to a job, sport, or activity and does not have much experience yet. You are often called this during your first year of doing something.
n. a person in their first year of a sport or profession; a novice or beginner. Informal in register, though standard in North American sports contexts.
The rookie made a mistake during his first game.
Even though she is a rookie in the sales department, she has already closed three major deals.
The veteran players spent the afternoon mentoring the rookies, ensuring the newcomers understood the team's complex defensive strategies before the season opener.
Thought to be an alteration of recruit + -ie, or from rook (“a cheat”) + -ie. Another possible origin is Dutch broekie (short for broekvent (“a boy still in short trousers”)), a common term for a shipmate. Also suggested is Irish rúca (“an inexperienced person”).
Commonly used as a noun, but can also function as a modifier before another noun, such as 'rookie mistake' or 'rookie season'.