Definition of Exceptional Circumstances
Conditions which are out of the ordinary course of events; unusual or extraordinary circumstances. Lack of original jurisdiction to hear and determine a case constitutes “exceptional circumstance” as basis for raising question for the first time on habeas corpus. Wesley v. Schneckloth, 55 Wash.2d 90, 346 P.2d 658, 660.
That's the definition of Exceptional Circumstances in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.