Main Entry: 1oc·ca·sion Pronunciation: &-'kA-zh&n Function: noun Etymology: Middle English, from Middle French or Latin; Middle French, from Latin occasion-, occasio, from occidere to fall, fall down, from ob- toward + cadere to fall -- more at OB-, CHANCE 1 : a favorable opportunity or circumstance 2 a : a state of affairs that provides a ground or reason b : an occurrence or condition that brings something about; especially : the immediate inciting circumstance as distinguished from the fundamental cause 3 a : HAPPENING, INCIDENT b : a time at which something happens : INSTANCE 4 a : a need arising from a particular circumstance b archaic : a personal want or need -- usually used in plural 5 plural : AFFAIRS, BUSINESS 6 : a special event or ceremony : CELEBRATION - on occasion : from time to time