aboard board做动词有上车/船/飞机的意思,boarding就是正在上.board做名词有板的意思,车厢地板的板. a是个词根,有三种意思:1. 以某种状态或方式,如: ablaze, afire, aflame, alight, aloud, alive, afloat等2. at, in, on, to sth,如: abed, aboard, abroad, ahead, afoot, ashore等3. not/without, 如: amoral, asexual, atyp…