1.  downfall(n = noun.event) ruin, ruination - failure that results in a loss of position or reputation;
is a kind of failure
has particulars: finish

2.  downfall(n = noun.phenomenon) precipitation - the falling to earth of any form of water (rain or snow or hail or sleet or mist);
is a kind of atmospheric condition, conditions, weather, weather condition
has parts: diamond dust, frost mist, frost snow, ice crystal, ice needle, poudrin, snow mist
has particulars: fine spray, hail, rain, rainfall, sleet, snow, snowfall, virga

3.  downfall(n = noun.event) fall - a sudden decline in strength or number or importance; "the fall of the House of Hapsburg"
is a kind of weakening
has particulars: anticlimax

downfall, n.
1 a a fall from prosperity or power. b the cause of this.
2 a sudden heavy fall of rain etc.

N  failure, nonsuccess, nonfulfillment, dead failure, successlessness, abortion, miscarriage, brutum fulmen, labor in vain, no go, inefficacy, inefficaciousness, vain attempt, ineffectual attempt, abortive attempt, abortive efforts, flash in the pan, lame and impotent conclusion, frustration, slip 'twixt cup and lip, blunder, fault, omission, miss, oversight, slip, trip, stumble, claudication, footfall, false step, wrong step, faux pas, titubation, b_evue, faute, lurch, botchery, scrape, mess, fiasco, breakdown, flunk, mishap, split, collapse, smash, blow, explosion, repulse, rebuff, defeat, rout, overthrow, discomfiture, beating, drubbing, quietus, nonsuit, subjugation, checkmate, stalemate, fool's mate, fall, downfall, ruin, perdition, wreck, deathblow, bankruptcy, losing game, affaire flamb_ee, victim, bankrupt, flunker, flunky, unsuccessful, successless, failing, tripping, at fault, unfortunate, abortive, addle, stillborn, fruitless, bootless, ineffectual, ineffective, inconsequential, trifling, nugatory, inefficient, insufficient, unavailing, of no effect, aground, grounded, swamped, stranded, cast away, wrecked, foundered, capsized, shipwrecked, nonsuited, foiled, defeated, struck down, borne down, broken down, downtrodden, overborne, overwhelmed, all up with, ploughed, plowed, plucked, lost, undone, ruined, broken, bankrupt, played out, done up, done for, dead beat, ruined root and branch, flambe, knocked on the head, destroyed, frustrated, crossed, unhinged, disconcerted dashed, thrown off one's balance, thrown on one's back, thrown on one's beam ends, unhorsed, in a sorry plight, hard hit, stultified, befooled, dished, hoist on one's own petard, victimized, sacrificed, wide of the mark, out of one's reckoning, left in the lurch, thrown away, unattained, uncompleted, unsuccessfully, to little or no purpose, in vain, re infecta, the bubble has burst, the jig is up, the game is up, all is lost, the devil to pay, parturiunt montes, dies infaustus, tout est perdu hors l'honneur.

N  adversity, evil, failure, bad luck, ill luck, evil luck, adverse luck, hard fortune, hard hap, hard luck, hard lot, frowns of fortune, evil dispensation, evil star, evil genius, vicissitudes of life, ups and downs of life, broken fortunes, hard case, hard lines, hard life, sea of troubles, peck of troubles, hell upon earth, slough of despond, trouble, hardship, curse, blight, blast, load, pressure, pressure of the times, iron age, evil day, time out of joint, hard times, bad times, sad times, rainy day, cloud, dark cloud, gathering clouds, ill wind, visitation, infliction, affliction, bitter pill, care, trial, the sport of fortune, mishap, mischance, misadventure, misfortune, disaster, calamity, catastrophe, accident, casualty, cross, reverse, check, contretemps, rub, backset, comedown, setback, losing game, falling, fall, downfall, ruination, ruinousness, undoing, extremity, ruin, unfortunate, unblest, unhappy, unlucky, improsperous, unprosperous, hoodooed, luckless, hapless, out of luck, in trouble, in a bad way, in an evil plight, under a cloud, clouded, ill off, badly off, in adverse circumstances, poor, behindhand, down in the world, decayed, undone, on the road to ruin, on its last legs, on the wane, in one's utmost need, planet-struck, devoted, born under an evil star, born with a wooden ladle in one's mouth, ill-fated, ill-starred, ill-omened, adverse, untoward, disastrous, calamitous, ruinous, dire, deplorable.

N  destruction, waste, dissolution, breaking up, diruption, disruption, consumption, disorganization, fall, downfall, devastation, ruin, perdition, crash, eboulement, smash, havoc, delabrement, debacle, break down, break up, fall apart, prostration, desolation, bouleversement, wreck, wrack, shipwreck, cataclysm, washout, extinction, annihilation, destruction of life, knock-down blow, doom, crack of doom, destroying, demolition, demolishment, overthrow, subversion, suppression, abolition, biblioclasm, sacrifice, ravage, razzia, inactivation, incendiarism, revolution, extirpation, beginning of the end, commencement de la fin, road to ruin, dilapidation, sabotage, destroyed, perishing, trembling to its fall, nodding to its fall, tottering to its fall, in course of destruction, extinct, all-destroying, all-devouring, all-engulfing, destructive, subversive, ruinous, devastating, incendiary, deletory, destroying, suicidal, deadly, with crushing effect, with a sledge hammer, delenda est Carthago, dum Roma deliberat Saguntum perit, ecrasez l'infame.

N  descent, descension, declension, declination, fall, falling, slump, drop, plunge, plummet, cadence, subsidence, collapse, lapse, downfall, tumble, slip, tilt, trip, lurch, cropper, culbute, titubation, stumble, fate of Icarus, avalanche, debacle, landslip, landslide, declivity, dip, hill, rappel, descending, descendent, decurrent, decursive, labent, deciduous, nodding to its fall, downhill, downwards, the bottom fell out.