unavailability,n. The status or condition of not being available, as when a witness is exempted by court order from testifying. • Unavailability is recognized under the Federal Rules of Evidence as an exclusion to the hearsay rule. Fed. R. Evid. 804. [Cases: Criminal Law  419(5); Evidence  317(17). C.J.S. Criminal Law § 860; Evidence §§ 259–260.]
[Blacks Law 8th]