Source : Webster's Revised Unabridged Dictionary (1913)

Disinheritance \Dis`in*her"it*ance\, n.
   The act of disinheriting, or the condition of being;
   disinherited; disherison.

Source : WordNet®

disinheritance
     n : the act by a donor that terminates the right of a person to
         inherit