rookie

Etymology

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”).

noun

1. An inexperienced recruit, especially in the police or armed forces.
2. A novice.
3. An athlete either new to the sport or to a team or in his first year of professional competition, especially said of baseball, basketball, hockey and American football players.
4. (Britain) A type of firecracker, used by farmers to scare rooks.

adj

1. non-professional; amateur
   The game was going well until I made that rookie mistake.
   the rookiest of rookie mistakes