collapse
This word carries a heavy sense of suddenness and total failure. It is not a gradual decline but a catastrophic break. When used for buildings, it evokes a violent, noisy descent. When used for people, it suggests a total loss of consciousness or strength, often implying a medical emergency or extreme fatigue. In a systemic sense, it describes a complete breakdown of order or economy where the internal support structures vanish. It is more final and dramatic than words like fail or decline, suggesting that the entity cannot simply be repaired but must be entirely rebuilt from the rubble.
Countable when referring to a specific event of falling, such as a building collapse. Uncountable when referring to the general state of failure, such as the collapse of civilization.
Meanings
To fall down suddenly because of weakness or lack of support.
"The old shed collapsed under the weight of the snow."
To fall down suddenly from exhaustion, illness, or shock.
"The marathon runner collapsed just before the finish line."
To fold something into a smaller, more compact shape.
"You can collapse the chair for easy storage."
A sudden failure of an institution, system, or structure.
"The stock market collapse caused widespread panic."