Litigant (noun): A person who has civil legal case. (विवादी , मुक़दमेबाज)
Synonyms: Claimant, Appellant, Plaintiff, Contestant
Antonyms: Ally, Colleague, Supporter
Example: When the litigant interrupted the proceedings again and again, the judge sent him to jail.
No doubt, in some cases, prejudice is presumed — for example, where a judge has appeared for one of the litigants at some stage in the same dispute.