I did not know his nephew Jack became a leatherneck.我不知道他的侄子杰克已加入海军陆战队....

n.海军陆战队员...

leathern的音标：leathern的英式发音音标为：['leðən]leathern的美式发音音标为：['leðən]...

leatherneck的音标：leatherneck的英式发音音标为：['leðənek]leatherneck的美式发音音标为：['leðəˌnek]...

adj.皮的，皮（革）制的，似皮（革）的...