n. & v.
--n.
1. the tumbling down or falling in of a structure; folding up; giving way.
2 a sudden failure of a plan, undertaking, etc.
3 a physical or mental breakdown.
--v.
1. a intr. undergo or experience a collapse. b tr. cause to collapse.
2 intr. colloq. lie or sit down and relax, esp. after prolonged effort (collapsed into a chair).
3 a intr. (of furniture etc.) be foldable into a small space. b tr. fold (furniture) in this way.
Derivatives:
collapsible adj. collapsibility n.
Etymology: L collapsus past part. of collabi (as COM-, labi slip)