1ADV [ADVERB after verb]在(摩托车或自行车的)后座上 If someone rides pillion on a motorcycle or bicycle, they sit behind the person who is controlling it. 在(摩托车或自行车的)后座上
She rode pillion on her son's motor bike.
她坐在儿子摩托车的后座上。
2N-COUNT [oft NOUN n](摩托车的)后座 On a motorcycle, the pillion is the seat or part behind the rider. (摩托车的)后座
As a learner rider you must not carry a pillion passenger.