The Collaborative International Dictionary of English v.0.48:
Disinheritance \Dis`in*her"it*ance\, n. The act of disinheriting, or the condition of being; disinherited; disherison. [1913 Webster]WordNet (r) 3.0 (2006):
disinheritance n 1: the act by a donor that terminates the right of a person to inherit