tourist

Tourist is built from tour plus the suffix -ist. Tour traces back through Old French torner and Latin tornō ('to turn') to Latin tornus, a turning-tool borrowed from Greek τόρνος (tórnos), itself from a Proto-Indo-European root meaning 'to turn.' The -ist ending comes through Old French -iste, Latin -ista, and Greek -ιστής, marking a person who does something.

The word tour once carried the sense of turning or a circuit, and tourist simply names the person who makes that circuit — someone who goes on a tour.

It's a doublet of turista, another English word descended from the same Latin-through-Old French line as tour.