A more thorough explanation:

Definition: To litigate (a case or matter) again or anew.

Example: The defendant's lawyer plans to relitigate the case in a higher court.

Explanation: This means that the defendant's lawyer wants to take the case to a higher court and argue it again, even though it has already been decided in a lower court. The term "relitigate" implies that the case has already been litigated once before.