The Collaborative International Dictionary of English v.0.48:

Averruncate \Av`er*run"cate\, v. t. [L. averruncare to avert; a,
   ab, off + verruncare to turn; formerly derived from ab and
   eruncare to root out. Cf. Aberuncate.]
   1. To avert; to ward off. [Obs.] --Hudibras.
      [1913 Webster]

   2. To root up. [Obs.] --Johnson.
      [1913 Webster]