IPA: /ˈtræv.əl.ər/
KK: /ˈtrævələr/
A person who goes on journeys, especially to faraway places.
The traveller explored many countries during her summer vacation.
Traveller → It is formed from "travel" (from Old French *travailler*, meaning to work or toil) and "-er" (meaning a person who). A traveller is a person who works or toils at moving from one place to another.
Think of someone who is 'toiling' or 'working' ('travailler') to move from one place to another — that's what a traveller does.