- Cave in - Fall in - Implosion - 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. - 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. - A falling together suddenly, as of the sides of a hollow
vessel. - A sudden and complete failure; an utter failure of any
kind; a breakdown.