n An instigation or antagonization intended to convince a person to perform an action they otherwise would not.
n A difficult task, especially one that the person making the attempt finds more enjoyable because of that difficulty.
n (legal|rare) A judge's interest in the result of the case for which he or she should not be allowed to sit the case, e.g. a conflict of interest.
n (legal) The act of seeking to remove a judge, arbitrator or other judicial or semi-judicial figure for reasons of alleged bias or incapacity.