In feudal law. The vassals of a lord who sat In his court as judges of their co-vassals, and were called “peers,” as being each other’s equals, or of the same condition. The nobility of Great Britain, being the lords temporal having seats in parliament, and including dukes, marquises, earls, viscounts, and barons. Equals; those who are a man’s equals in rank and station; this being the meaning in the phrase “trial by a jury of his peers.”
PEERS
TheLaw.com Law Dictionary & Black's Law Dictionary 2nd Ed.