recuse
v. to refuse to be a judge (or for a judge to agree to a request by one of the parties to step aside) in a lawsuit or appeal because of a conflict of interest or other good reason (acquaintanceship with one of the parties, for example). It also applies to a judge or prosecutor being removed or voluntarily removing himself/herself from a criminal case in which he/she has a conflict of interest, such as friendship or known enmity to the defendant.