first mate

n. 大副(商船上的头衔, 仅低于船长)

例句与用法：

At thirty, he signed on as first mate with a cargo ship.

他30岁时受雇于一艘货船当了大副。

The first mate was studying to become a master.

大副正在学习准备当船长。

详细释义：

ph.

大副(地位仅次于船长)