1.NounAn ongoing relationship between (usually two) rivals who compete for superiority.
"The Boston Bruins have a longstanding rivalry with the Montreal Canadiens.; James and Polly have a bitter rivalry due to the latter's inclusion in the Tea Time Teaser."
2.NounThe characteristic of being a rivalrous good, such that it can be consumed or used by only one person at a time.
"Common goods are those which are rivalrous in consumption but non-excludable"
3.NounAny competition between two or more things or factors.
"Binocular rivalry is a visual phenomenon in which perception alternates between different images presented to each eye."