Applicable statutes or canons of ethics may provide standards for recusal in a given proceeding or matter. Providing that the judge or presiding officer must be free from disabling conflicts of interest makes the fairness of the proceedings less likely to be questioned.
https://en.wikipedia.org/wiki/Judicial_disqualification
The verb RECUSE has 2 senses: 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. Familiarity information: RECUSE used as a verb is rare.
http://www.audioenglish.org/dictionary/recuse.htm
Grounds for Recusal. Motions to recuse or disqualify judges and other adjudicators have been made for all sorts of reasons. Most commonly such motions are predicated upon a claim that the judge is biased in favor of one party, or against another, or that a reasonable objective observer would think he might be.
http://www.judicialrecusal.com/grounds-for-recusal/
1. Leslie Abramson, of the Louis Brandeis School of Law at the University of Louisville wrote an early (1993) article on the grounds for judicial disqualification (in federal practice). See Abramson, L., Specifying Grounds for Judicial Disqualification in Federal Courts, Nebraska Law Review, Vol. 72, No. 1046 (1993).
http://www.judicialrecusal.com/grounds-for-recusal/
In the United States, the term recusal is used most often with respect to court proceedings. Two sections of Title 28 of the United States Code (the Judicial Code) provide standards for judicial disqualification or recusal.
https://en.wikipedia.org/wiki/Judicial_disqualification
Since then, Hoboken's mayor has accused Christie's administration of pressuring her to approve a development project with ties to Samson's law firm, and a published report questioned why Samson didn't.
http://www.thefreedictionary.com/recuse
This is referred to in the United States as the extra-judicial source rule and was recognized as a general presumption, although not an invariable one, in the 1994 U.S. Supreme Court decision in Liteky v. United States.
https://en.wikipedia.org/wiki/Judicial_disqualification
re·cuse. tr.v. re·cused, re·cus·ing, re·cus·es. To disqualify or seek to disqualify (a judge or juror) from participation in the decision in a case, as for personal prejudice against a party or for personal interest in the outcome.
http://www.thefreedictionary.com/recuse
The general rule is that, to warrant recusal, a judge's expression of an opinion about the merits of a case, or his familiarity with the facts or the parties, must have originated in a source outside the case itself.
https://en.wikipedia.org/wiki/Judicial_disqualification
For a listing of Judicial Policy Advisory Opinions, many of which deal with the subject of when a federal judge is subject to recusal or disqualification click here http://www.uscourts.gov/uscourts/RulesAndPolicies/conduct/Vol02B-Ch02.pdf. 4.
http://www.judicialrecusal.com/grounds-for-recusal/
what is it to recuse oneself
It is to recuse Disqualify oneself  in a particular case. To recuse oneself is to disqualify oneself as a judge in a particular case.