Definition of 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