The Collaborative International Dictionary of English v.0.48:

disherit \dis*her"it\ (d[i^]s*h[e^]r"[i^]t), v. t. [imp. & p. p.
   Disherited; p. pr. & vb. n. Disheriting.] [F.
   d['e]sh['e]riter; pref. d['e]s- (L. dis-) + h['e]riter to
   inherit. See Inherit, and cf. Dusheir, Disinherit.]
   To disinherit; to cut off, or detain, from the possession or
   enjoyment of an inheritance. [Obs.] --Spenser.
   [1913 Webster]