aboard
词形变化：
同义词：
on | on board | board | on the bus | on the train | onboard | inside | on to | involved | on the team | or | a | train | airplane | on base | alongside |
反义词：
ashore |
词义辨析：
同义:
prep.在……上; 进入
on board
on (or into) a ship, train or airplane
反义:
ad.在船(或飞机, 车)上
ashore