Peer was the title of a member of a Quorum that presided over the process of T'Kal-in-ket on Ni'Var. One of the Peers was appointed as chair and they could dismiss the challenge with unanimous consensus from the other two Peers.
In 3189, Michael Burnham faced a Quorum consisting of Peers V'Kir, N'Raj, and Shira during her T'Kal-in-ket to gain access to the SB-19 data. (DIS: "Unification III")