1.  event(n = noun.tops) - something that happens at a given place and time;
is a kind of psychological feature
has particulars: act, deed, human action, human activity, group action, might-have-been, nonevent, happening, natural event, occurrence, occurrent, social event, miracle, migration, make-up, makeup, zap, fall

2.  event(n = noun.state) case - a special set of circumstances; "in that event, the first possibility is excluded"; "it may rain in which case the picnic will be canceled"
is a kind of circumstance

3.  event(n = noun.phenomenon) - a phenomenon located at a single point in space-time; the fundamental observational entity in relativity theory;
is a kind of physical phenomenon

4.  event(n = noun.phenomenon) consequence, effect, issue, outcome, result, upshot - a phenomenon that follows and is caused by some previous phenomenon; "the magnetic effect was greater when the rod was lengthwise"; "his decision had depressing consequences for business"; "he acted very wise after the event"
is a kind of phenomenon
has particulars: materialisation, materialization, offspring, aftereffect, aftermath, backwash, wake, bandwagon effect, brisance, butterfly effect, by-product, byproduct, change, coattails effect, coriolis effect, dent, domino effect, harvest, impact, wallop, influence, knock-on effect, branch, offset, offshoot, outgrowth, product, placebo effect, position effect, repercussion, reverberation, response, fallout, side effect, spillover
Derived form verb eventuate₁

1.  That which comes, arrives, or happens; that which falls out; any incident, good or bad. Macaulay. [1913 Webster]
"To watch quietly the course of events." [1913 Webster]
"There is one event to the righteous, and to the wicked." [1913 Webster]

2.  An affair in hand; business; enterprise. Shak. [1913 Webster]

3.  The consequence of anything; the issue; conclusion; result; that in which an action, operation, or series of operations, terminates. [1913 Webster]
"Dark doubts between the promise and event."

   To break forth. B. Jonson. [1913 Webster]

event, n.
1 a thing that happens or takes place, esp. one of importance.
2 a the fact of a thing's occurring. b a result or outcome.
3 an item in a sports programme, or the programme as a whole.
4 Physics a single occurrence of a process, e.g. the ionization of one atom.
5 something on the result of which money is staked.

Idiom:
at all events (or in any event) whatever happens. event horizon Astron. the gravitational boundary enclosing a black hole, from which no light escapes. in the event as it turns (or turned) out. in the event of if (a specified thing) happens. in the event that disp. if it happens that.

Etymology:
L eventus f. evenire event- happen (as E-, venire come)

N  contention, strife, contest, contestation, struggle, belligerency, opposition, controversy, polemics, debate, war of words, logomachy, litigation, paper war, high words, sparring, competition, rivalry, corrivalry, corrivalship, agonism, concours, match, race, horse racing, heat, steeple chase, handicap, regatta, field day, sham fight, Derby day, turf, sporting, bullfight, tauromachy, gymkhana, boat race, torpids, wrestling, greco-roman wrestling, pugilism, boxing, fisticuffs, the manly art of self-defense, spar, mill, set-to, round, bout, event, prize fighting, quarterstaff, single stick, gladiatorship, gymnastics, jiujitsu, jujutsu, kooshti, sumo, athletics, athletic sports, games of skill, shindy, fracas, clash of arms, tussle, scuffle, broil, fray, affray, affrayment, velitation, colluctation, luctation, brabble, brigue, scramble, melee, scrimmage, stramash, bushfighting, free fight, stand up fight, hand to hand, running fight, conflict, skirmish, rencounter, encounter, rencontre, collision, affair, brush, fight, battle, battle royal, combat, action, engagement, joust, tournament, tilt, tilting, tournay, list, pitched battle, death struggle, struggle for life or death, life or death struggle, Armageddon, hard knocks, sharp contest, tug of war, naval engagement, naumachia, sea fight, duel, duello, single combat, monomachy, satisfaction, passage d'armes, passage of arms, affair of honor, triangular duel, hostile meeting, digladiation, deeds of arms, feats of arms, appeal to arms, pugnacity, combativeness, bone of contention, contending, together by the ears, at loggerheads, at war, at issue, competitive, rival, belligerent, contentious, combative, bellicose, unpeaceful, warlike, quarrelsome, pugnacious, pugilistic, gladiatorial, palestric, palestrical, a verbis ad verbera, a word and a blow, a very pretty quarrel as it stands, commune periculum concordiam parit, lis litem generat.

N  eventuality, event, occurrence, incident, affair, matter, thing, episode, happening, proceeding, contingency, juncture, experience, fact, matter of fact, naked fact, bare facts, just the facts, phenomenon, advent, business, concern, transaction, dealing, proceeding, circumstance, particular, casualty, accident, adventure, passage, crisis, pass, emergency, contingency, consequence, opportunity (occasion), the world, life, things, doings, affairs in general, things in general, affairs in general, the times, state of affairs, order of the day, course of things, tide of things, stream of things, current of things, run of things, march of things, course of events, ups and downs of life, vicissitudes of life, chapter of accidents, situation, happening, going on, doing, current, in the wind, in the air, afloat, on foot, afoot, on the tapis, at issue, in question, incidental, eventful, stirring, bustling, full of incident, memorable, momentous, signal, eventually, in the event of, in case, just in case, in the course of things, as things, times go, as the world goes, wags, as the tree falls, cat jumps, as it may turn out, happen, that's the way the ball bounces, that's the way the cookie crumbles, you never know what may turn up, you never know what the future will bring, the plot thickens, breasts the blows of circumstance, so runs round of life from hour to hour, sprinkled along the waste of years.

blessed event, chance event, diving event, dramatic event, event horizon, event planner, field event, happy event, in any event, natural event, news event, periodic event, recurrent event, sales event, social event, spacecraft event time, swimming event, three-day event, track event