The Collaborative International Dictionary of English v.0.48:

recuse \re*cuse"\ (r?*k?z"), v. t. [F. r['e]cuser, or L.
   recusare. See Recusant.] (Law)
   To refuse or reject, as a judge; to challenge that the judge
   shall not try the cause. [Obs.] --Sir K. Digby.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

recuse \re*cuse"\ (r?*k?z"), v. i.
   To withdraw oneself from serving as a judge or other
   decision-maker in order to avoid a real or apparent conflict
   of interest; -- often used with the reflexive; as, the judge
   recused himself due to a financial interest in the matter.
   [PJC]

WordNet (r) 3.0 (2006):

recuse
    v 1: disqualify oneself (as a judge) in a particular case
    2: challenge or except to a judge as being incompetent or
       interested, in canon and civil law