Vis major

1.

(Law) A superior force which under certain circumstances is held to exempt from contract obligations; inevitable accident; - a civil-law term used as nearly equivalent to, but broader than, the common-law term act of God (which see).

Noun

1.

vis major - a natural and unavoidable catastrophe that interrupts the expected course of events; "he discovered that his house was not insured against acts of God" Synonyms: act of God, force majeure, inevitable accident, unavoidable casualty

VIS MAJOR, a superior force. In law it signifies inevitable accident.
     2. This term is used in the civil law in nearly the same same way that the words act of God, (q.v.) are used in the common law. Generally, no one is responsible for an accident which arises from the vis major; but a man may be so where he has stipulated that he would; and when he has been guilty of a fraud or deceit. 2 Kent, Com. 448; Poth. Pret a Usage, n. 48, n. 60 Story Bailm. Sec. 25.

act of God, calamity, cataclysm, catastrophe, disaster, force majeure, inevitable accident, tragedy, unavoidable casualty