Yours, Etc.: Origins and Uses of 8 Sign-Offs
1650s, "physician, medical student," from Latin medicus "physician" (see medical (adj.)); modern sense of "serviceman in a military medical corps" first recorded 1925.
medic med·ic (měd'ĭk)n.
A member of a military medical corps.
A physician or surgeon.
A medical student or intern.