Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
passer-by is a noun meaning "a person who passes by casually or by chance". It carries one recorded sense.
a person who passes by casually or by chance
Definitions, synonyms and semantic relations for passer-by come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.