aboard
/əˈbɔ:d; ə`bɔrd/ adv
part, prep on or into a ship, an aircraft, a train or (esp US) a bus 在船, 飞机, 火车或公共汽车上（在美式英语中尤指公共汽车）; 上船, 飞机, 火车或公共汽车
We went/climbed aboard. 我们上了船（或飞机, 车等）.
Welcome aboard! 欢迎乘坐这船（或飞机, 车等）!
All aboard! ie The ship, etc is about to depart. 请各位上船（或飞机, 车等）!
He was already aboard the ship. 他已经上船了.