The word 'passerby' is correct and usable in written English.
You can use it to refer to a person who passes by, usually staying only a short time. For example, "The passerby hurried past my window, not stopping to take a closer look."
A recent incident caught on camera by a passerby at the Manchester Fort Shopping Park has highlighted just how easy it is to stop people being able to use their remote central locking car keys.
I'll be walking to the shops, clenching and re-clenching my fists, not realising what I'm doing until a passerby looks at me, alarmed.
Antony describes how he came out of the train station the night before, only for a car to pull up and those inside to jump out and bottle a passerby.
"Because of Ebola?" a shocked passerby asked.
(In a tragic moment in the video, before police arrive, a passerby advises him to back down: "That's not the way you do it, man").
Whether promoting a product, an event, or a sentiment (such as patriotism), a poster must immediately catch the attention of the passerby.
A temple column with a message carved on it is not a book nor is a sign or placard, which, though it may be easy enough to transport, is made to attract the eye of the passerby from a fixed location.
A traveler who encounters either a funeral procession, the source of running water, or a passerby carrying a pitcher of water is considered to have good fortune awaiting.
A bemused passerby asks, "Is there a pop concert on tonight or something?" Nope, this crowd is here for WWE's weekly live show, Raw.
The most famous case of ricin poisoning was in 1978 when dissident Bulgarian writer Georgi Markov was killed after a passerby in London jabbed him with an umbrella that injected a tiny ricin-filled pellet.
An unidentified passerby filmed the incident from the moment Slager, 33, and Scott appeared to briefly scuffle before Scott began to run away.
