litigant:
(plural: ‘litigants‘; pronunciation: the letters ‘i’ rhyme with the letter ‘i’ in “ink” and the letter ‘g’ rhymes with the letter ‘g’ in “gun”.)

a judge discussing with litigants in a courtroom
a person who has some disagreement, dispute, quarrel, fight, etc. with somebody else and approaches a court of law for settlement;
a person who always argues with others even over simple silly matters (nothing to do with a court of law),

a litigant (quarrelsome person)
A plaintiff and a defendant in a law suit are both litigants., i.e. a person who says he/she has been cheated or hurt by somebody and the person who is said to have cheated or hurt somebody are both called ‘litigants’.
A vexatious litigant is a litigant who has approached one or more courts of law repeatedly in order to put the other party to inconvenience and is looked down upon as an abuser of justice system, and, therefore, is often subjected to sanctions by the courts.
Each office or organisation is bound have a couple of litigants who get into disagreements or disputes with other members or employees and disrupt the day to day routine.
