Dedimus potestatem (which translates to “we have given the power”) is an outdated term that refers to some special authority granted to an individual by a court. In American law, the term means authority given to someone to depose a witness. However, in English law, the term can mean other powers as well like a client granting decision making authority to their attorney.
[Last updated in June of 2021 by the Wex Definitions Team]