passerby

A passerby is a person who happens to be passing through a place at a given time, typically on foot, and who is not the primary subject of attention. The term describes someone who is merely moving past rather than staying to participate in an event. Passersby are often referenced in reports of accidents, crimes, or other incidents to indicate ordinary people who happened to be nearby.

In English, the singular form is passerby and the plural is passersby or passers-by. The word is used to denote someone who is on the move past a scene rather than someone who is stationary or directly involved. It can also imply a potential but non-participating witness.

The term is distinct from bystander, which generally refers to a person who is present at an event and may remain in place to observe or intervene. A passerby’s relevance to a situation often rests on their proximity or the timing of their movement rather than any role they play in the event itself.

Etymology is straightforward: the word combines passer, meaning one who passes, with by, indicating location or proximity, and has appeared in English since the late Middle Ages. Variants include passers-by and passersby.

See also: pedestrian, bystander, witness, urban safety.