A person who is passing by (that is, walking past).
When he tripped and fell in the street, several kind passers-by helped him up.
Passer-by Sentence Examples
The sight raises the heartbeat of the passer-by who momentarily imagines this is an otter.
The wailing cry' and the frantic gestures of the cock bird in the breeding-season will tell any passer-by that a nest or brood is near; but, unless he knows how to look for it, nothing save mere chance will enable him to find it.
The bakery's typical pastries, doughnuts and other baked goods tempt the passer-by, while there are also healthy lunch-type foods like salads and sandwiches.