1.an event that occurs at a critical time;
at such junctures he always had an impulse to leave
2.a vaguely specified social event;
the party was quite an affair
3.reason;
there was no occasion for complaint
4.the time of a particular event;
on the occasion of his 60th birthday
5.an opportunity to do something;
there was never an occasion for her to demonstrate her skill
1.give occasion to