Borrowed from Old Occitan viatge and Old French viage, veiage, from Latin viāticum, from the adjective viāticus, from via (“road, path”) + -āticus (“pertaining to”). By surface analysis, via + -aggio.
Doublet of viatico and cognate to Catalan viatge, French and English voyage, Spanish viaje, Portuguese viagem, Norman viage, Sicilian viaggiu, Maltese vjaġġ, Romanian voiaj.