greenhorn

詳細解釋：

green.horn

n.（名詞）
An inexperienced or immature person, especially one who is easily deceived.
生手，新手：一個沒有經驗、幼稚的人，尤指易受騙的人
A newcomer, especially one who is unfamiliar with the ways of a place or group.
新來者：新來的人，尤指對一地或一群人還不了解的人

來源：
Middle English greene horn [horn of a newly slaughtered animal]
中古英文 greene horn [剛殺的動物的角]
grene [green] * see green
grene [綠色的] *參見 green
horn [horn] * see horn
horn [角] *參見 horn