Verb
1. 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"2. collapse due to fatigue, an illness, or a sudden attack
3. fold or close up;
"fold up your umbrella""collapse the music stand"4. fall apart;
"the building crimbled after the explosion""Negociations broke down"5. cause to burst;
"The ice broke the pipe"6. suffer a nervous breakdown
7. lose significance, effectiveness, or value;
"The school system is collapsing""The stock market collapsed"