To adjudicate is to act like a judge. A judge might adjudicate a case in court, and you may have to adjudicate in the local talent show.
Do you see a similarity between judge and adjudicate? When you add the common Latin prefix ad meaning "to" or "toward," you have a pretty good idea what the word means. But a judge isn't the only person who can adjudicate. If you're fighting with your little brother or sister and make them cry, your parents may adjudicate and send you to your room.
v put on trial or hear a case and sit as the judge at the trial of
v bring to an end; settle conclusively
determine the result of (a competition)
decide how much is to be paid on an insurance claim
be a referee or umpire in a sports competition