I did not know that yesterday!

Although the term "rookie" is used mostly to describe first-year athletes, it can refer to anyone new on the job. There are rookie cops, rookie rodeo clowns, even rookie presidents. You name the occupation, and odds are it's got rookies in way over their heads.

ESPN credits author Rudyard Kipling with the first usage. In his "Barrack-Room Ballads," published in 1892, Kipling writes "So 'ark an' 'eed you rookies/Which is grumblin' sore."

Ask Oxford believes "rookie" might be an alteration of the word "recruit." Eh, maybe so, but that's a pretty dull explanation. The Word Detective postulates a different and far more interesting theory. They believe "rookie" comes from "rook," a European and Asian bird famous for annoying farmers.

According to the Word Detective, in the 16th century the word "came into use as a disparaging epithet for a person of low repute" and later applied to the easily conned or fooled. See the connection? 1.) A rook is an annoying bird. 2.) Rook becomes slang for a disliked person. 3.) Rook comes to mean a gullible person. 4.) Those with experience call the newer workers "rooks" because they're believed to be easily fooled.

And there ya have it -- the rookie's roundabout story.

source: ask.yahoo.com