passer-by
n
(pl passers-by ) person who is going past sb/sth, esp by chance 过路人; (尤指)偶然路过的人
Police asked passers-by if they had seen the accident happen. 警察询问过路的人是否见到事故发生的经过.
The captain knew that another attempt would be made later, for the sunken ship he was trying to find had been carrying a precious cargo of gold bullion.