traveller vs fellow traveler

Other hyponyms of traveller include absentee, air traveler, air traveller, arrival, arriver, comer, astronaut, cosmonaut, spaceman, business traveler, bearer, carrier, toter, companion, fellow traveller, entrant, flier, flyer, follower, alien, foreigner, noncitizen, outlander, hosteller, courier, messenger, migrant, migrator, motorcyclist, mover, musher, passenger, rider, footer, pedestrian, walker, rafter, raftman, raftsman, rider, rider, runner, scourer, bather, natator, swimmer, holidaymaker, tourer, tourist, transient, trekker, visitant, visitor, voyager, bird of passage, roamer, rover, wanderer, journeyer, wayfarer.