Definition of Emergency

A sudden unexpected happening; an unforeseen occurrence or condition; perplexing contingency or complication of circumstances; a sudden or unexpected occasion for action; exigency; pressing necessity. Emergency is an unforeseen combination of circumstances that calls for immediate action. State v. Perry, 29 Ohio App.2d 33, 278 N.E.2d 50, 53. See also Emergency doctrine; Sudden emergency doctrine.

That's the definition of Emergency in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.