Source : Webster's Revised Unabridged Dictionary (1913)

Instancy \In"stan*cy\, n.
   Instance; urgency. [Obs.]

         Those heavenly precepts which our Lord and Savior with
         so great instancy gave.                  --Hooker.

Source : WordNet®

instancy
     n 1: the quickness of action or occurrence; "the immediacy of
          their response"; "the instancy of modern communication"
          [syn: {immediacy}, {immediateness}, {instantaneousness}]
     2: urgently demanding attention; "the insistence of their
        hunger"; "he pressed his demand with considerable
        instancy" [syn: {imperativeness}, {insistence}, {insistency}]