According to the dictionary a Rookie is:
– a person who has just started a job or activity -or-
– 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.
The word ‘Rookie’ comes from recruit and -ie, thought to be an alteration of recruit, another reasonable origin is Dutch broekie (short for broekvent (“a boy still in short trousers”), a common term for a shipmate. (*Wiktionary)
According to Rookie Republic:
Rookies are motivated
Rookies are committed to their ideas
Rookies have a clear idea
Rookies are open minded
Rookies are not limited by education or background.
Rookies are entrepreneurs.
BE A ROOKIE.