Collapsed

Collapsed is the past participle of collapse, meaning to fall in, cave in, or fail suddenly. It is used as an adjective to describe something that has ended its previous structure or function, or as a verb phrase indicating that something has already given way. In everyday usage, a collapsed tent or bridge has fallen or buckled; a collapsed organization or plan has ceased to operate.

In science, the term appears in several contexts. In quantum mechanics, wavefunction collapse refers to the transition from a superposition of states to a single observed state when a measurement is made. This concept is central to certain interpretations of quantum theory and is a subject of ongoing discussion and debate. Collapse is also used more generally to describe abrupt changes or failures in systems, such as atmospheric collapse in models or structural collapse in engineering analyses.

In computing and information design, collapsed elements are UI components or data views that are hidden or summarized by default and can be expanded by the user. Collapsed views help conserve space in interfaces or documents and are commonly used in menus, accordions, or data tables.

In medicine, collapse can denote syncope, or fainting, a sudden loss of consciousness typically related to reduced blood flow to the brain. A collapsed lung, or pneumothorax, occurs when air enters the pleural space and prevents full lung inflation, requiring clinical assessment and treatment.

Etymology traces collapse to Latin collapsus, the past participle of collabi, meaning to fall together.