■ noun
1》 a particular event, or the time at which it takes place.
↘a suitable or opportune time.
2》 a special event or celebration.
3》 formal reason; cause: we have ~ to rejoice.
■ verb formal cause.
Phrases
on ~ from time to time.
rise to the ~ perform well in response to a special situation.
take ~ make use of an opportunity to do something.
Origin
ME: from L. occasio(n-) 'juncture, reason', from occidere 'go down, set'.