Definitions
1.NounAn inexperienced recruit, especially in the police or armed forces.
2.NounA novice.
3.NounAn athlete either new to the sport or to a team or in his/her first year of professional competition, especially said of baseball, basketball, hockey and American football players.
4.NounA type of firecracker, used by farmers to scare rooks.
5.AdjectiveNon-professional; amateur"The game was going well until I made that rookie mistake.; the rookiest of rookie mistakes"
6.VerbTo be a rookie; to go through one's inexperienced learning period in a job, team, or organization.
7.VerbTo haze one or more rookies as an initiation ritual.