Meaning

noun a line generated by a point on one figure rolling around a second figure

noun a wheel with teeth for making a row of perforations

noun a gambling game in which players bet on which compartment of a revolving wheel a small ball will come to rest in

originBorrowed from French roulette (“roulette, little wheel”). The sense "situation with a random chance of incurring serious harm" may be abstracted from Russian roulette.

Etymology from Wiktionary, CC BY-SA 3.0