A more thorough explanation:

Decern (di-sərn) is a verb used in Scots law to mean to decree or give a final judgment. In Scotland, before a judgment or interlocutor of any court can be extracted to warrant execution, it must import a decree. Therefore, all extractable judgments end with the word "decern."

• The judge will decern the case in favor of the plaintiff.
• The court decerned that the defendant pay damages to the victim.

These examples illustrate how decern is used in Scots law to mean to give a final judgment or decree. In both examples, the court is making a final decision in the case and issuing a decree that must be followed.