[noun] a mishap caused by something suddenly falling down or caving in
[noun] the act of throwing yourself down; "he landed on the bed with a great flop" Synonyms: flop
[noun] a sudden large decline of business or the prices of stocks (especially one that causes additional failures) Synonyms: crash
[verb] break down, literally or metaphorically; "The wall collapsed"; "The business collapsed"; "The dam broke"; "The roof collapsed"; "The wall gave in"; "The roof finally gave under the weight of the ice" Synonyms: fall in, cave in, give, give way, break, founder
[verb] collapse due to fatigue, an illness, or a sudden attack Synonyms: break down
[verb] fold or close up; "fold up your umbrella"; "collapse the music stand"