Origin of the word rookie

A rookie is someone new or recently promoted to a higher level of competition or responsibility.

The word is most commonly used in American sports commentary to describe a team player in their first season - a rookie NFL quarterback, for example, or a new player on the Ryder Cup team.

Where does the word rookie come from?

The etymological origin is uncertain. The OED suggests that it may be a corruption of the word recruit. Its first citation is from Rudyard Kipling's Barrack-Room Ballads (1892), referring to new recruits to the British army

So 'ark an' 'eed, you rookies, which is always grumblin' sore,