Doctor

Originally, a teacher in general; in the Middle Ages, an eminent theologian, as A quinas, Duns Scotus, Hales, Occam, Roger Bacon; in modern times, the holder of a degree, earned or honorary, conferred by an institution of learning. We have doctors of Medicine, M.D.; of Law, LL.D., D.C.L., or U.J.D.; of Divinity, D.D. or S.T.D.; of Philosophy, Ph.D.; of Letters, L.H.D.; of Music, Mus. Doc.; and of Science, D.Sc.