Round robin is also a type of athletic tournament, wherein each team or person participating plays every other team or person a predetermined number of times (usually once or twice).
High profile examples of round robin games include how many US college athletics are scheduled - each conference schedules all of the teams within it to play each other once (football, in the conferences with fewer members, field hockey, lacrosse, and so forth) or twice (ACC basketball, among many others). The finals of the CONCACAF qualifying tournament was a home and home round robin tournament.
Compare this with single- or double- elimination.