passer-by

noun, plural pass·ers·by [pas-erz-bahy, -bahy, pah-serz-] /ˈpæs ərzˈbaɪ, -ˌbaɪ, ˈpɑ sərz-/,

1. a person passing by.

noun plural passers-by

1. a person that is passing or going by, esp on foot

n.also passerby, 1560s, from agent noun of pass (v.) + by; earlier, this sense was in passager (see passenger).