Etymology: Latin collapsus, past participle of collabi, from com- + labi to fall, slide — more at sleep
1. to fall or shrink together abruptly and completely ; fall into a jumbled or flattened mass through the force of external pressure <a blood vessel that collapsed> 2. to break down completely ; disintegrate <his case had collapsed in a mass of legal wreckage — Erle Stanley Gardner> 3. to cave or fall in or give way <the bridge collapsed> 4. to suddenly lose force, significance, effectiveness, or worth <fears that the currency may collapse> 5. to break down in vital energy, stamina, or self-control through exhaustion or disease; especially to fall helpless or unconscious 6. to fold down into a more compact shape <a chair that collapses> transitive verb 1. to cause to collapse <buildings collapsed by an earthquake> 2. condense <collapse several stories into one> • collapsibility noun • collapsible adjective II. noun Date: 1801 1. a. a breakdown in vital energy, strength, or stamina b. a state of extreme prostration and physical depression (as from circulatory failure or great loss of body fluids) c. an airless state of all or part of a lung originating spontaneously or induced surgically 2. the act or action of collapsing <the cutting of many tent ropes, the collapse of the canvas — Rudyard Kipling> 3. a sudden failure ; breakdown, ruin 4. a sudden loss of force, value, or effect <the collapse of respect for ancient law and custom — L. S. B. Leakey>
New Collegiate Dictionary. 2001.