occasion

an event that occurs at a critical time; "at such junctures he always had an impulse to leave"; "it was needed only on special occasions"

a vaguely specified social event; "the party was quite an affair"; "an occasion arranged to honor the president"; "a seemingly endless round of social functions"

reason; "there was no occasion for complaint"

the time of a particular event; "on the occasion of his 60th birthday"

an opportunity to do something; "there was never an occasion for her to demonstrate her skill"

give occasion to