1. (v. i.) To fail suddenly and completely\, like something hollow when subject to too much pressure; to undergo a collapse; as, Maximilian's government collapsed soon after the French army left Mexico; many financial projects collapse after attaining some success and importance.

2. (v. i.) To fall together suddenly, as the sides of a hollow vessel; to close by falling or shrinking together; to have the sides or parts of (a thing) fall in together, or be crushed in together; as, a flue in the boiler of a steam engine sometimes collapses.

3. (n.) A falling together suddenly, as of the sides of a hollow vessel.

4. (n.) A sudden and complete failure; an utter failure of any kind; a breakdown.

5. (n.) Extreme depression or sudden failing of all the vital powers, as the result of disease, injury, or nervous disturbance.

OD Waterloo amiable weakness bankruptcy be brought down be felled be found wanting be ruined be struck down be traumatized beating become insolvent bend blow bouncing check break break down break out break up breakability breakage breakdown breaking up breakup brittleness burn out bust cascade catabasis cataclysm cataract catastrophe catch catch cold cave cave in cave-in changeableness chute circulatory collapse collapse come apart come down come down with come short come to naught come to nothing come unstuck comedown conk out conquering conquest contract crack crack up crack-up crackup crash crippling cropper crumble crumple daintiness damage deathblow debacle deceleration declension declination decline decline and fall decrescendo defeat deflate deflation defluxion delicacy descend descending descension descent destructibility destruction detriment dilapidation diminish diminuendo dip down disablement disappear disappearance disaster disintegrate disintegration disorganization disrepair disruption dissolution dissolve dive down downbend downcome downcurve downfall downflow downgrade downpour downrush downtrend downturn downward trend draining droop drop drop down drop off dropping drubbing dwindling ebb effeminacy encroachment erupt evaporate exhaust exhaustedness exhaustion fade fag fail failure faint fall fall away fall dead fall down fall flat fall in fall off fall short fall stillborn fall through fall to pieces falling fatigue fever fizzle out flag flimsiness fold fold up founder fragility frailty frangibility gasp get get bogged down get hung up get mired get tired give out give way go go bankrupt go broke go down go downhill go into receivership go into shock go soft go to pieces go to pot go to ruin go to smash go under go up gravitate gravitation grow weary harm hiding hit the skids hobbling human frailty hurt hurting impairment implode implosion incapacitation inclination indecisiveness infirmity of will infringement inherent vice injury inroad insolvency insufficient funds irresolution jade keel over kited check lack lag lambasting languish lapse lathering licking lightness lose altitude lose ground loss maiming mastery mayhem mischief moral weakness mutilation nervous breakdown nervous exhaustion nervous prostration neurasthenia nose dive not answer not hack it not make it not make out not measure up not stretch not suffice overcoming overdose overdraft overdrawn account overthrow overturn pant parachute pass out peg out peter out pine pitch play out plummet plummeting plunge poop out pounce pour down