1N-COUNT 新手;菜鸟;（尤指）新兵，新警员 A rookie is someone who has just started doing a job and does not have much experience, especially someone who has just joined the army or police force. 新手;菜鸟;（尤指）新兵，新警员 [mainly US, informal]
I don't want to have another rookie to train.
我不想再训练新兵了。
...a rookie police officer.
新上任的警官
2N-COUNT (第一年参加体育比赛的)新队员 A rookie is a person who has been competing in a professional sport for less than a year. (第一年参加体育比赛的)新队员 [US]