1. (n.) An important event; an occurrence; an incident\.

2. (n.) A favorable opportunity; a convenient or timely chance; convenience.

3. (n.) An occurrence or condition of affairs which brings with it some unlooked-for event; that which incidentally brings to pass an event, without being its efficient cause or sufficient reason; accidental or incidental cause.

4. (n.) Need; exigency; requirement; necessity; as, I have no occasion for firearms.

5. (n.) A reason or excuse; a motive; a persuasion.

6. (v. t.) To give occasion to; to cause; to produce; to induce; as, to occasion anxiety.

a leg up advantage adventure affair antecedent antecedents author bare necessities base basis bear beget break breed bring about bring forth bring on bring to effect bring to pass call call for call forth call up causation cause cause and effect celebration ceremony chance circumstance clear stage commemoration conceive condition conjuncture contingency create demand demand for desideration desideratum determinant determinative do effect effectuate element elicit engender episode essential essentials establish etiology event eventuality evoke excuse experience fact factor fair field fair game father found foundation function gala generate gestate give birth to give occasion to give origin to give rise to go ground grounds hap happening happenstance impel impulse inaugurate incident incitement indispensable induce inducement institute juncture justification liberty look-in make make for matter of fact milestone moment must must item necessaries necessities necessity need need for obligation observance occasionally occurrence on occasion opening opportunism opportunity originate particular party phenomenon place prerequirement prerequisite principle produce prompt prompting provocation provoke reality realize reason requirement requisite requisition right room scope set afloat set on foot set up shot show sire squeak stepping-stone stimulus the necessary the needful thing time turn of events want warrant work work up