pedagogue (n.)

late 14c., pedagoge, "schoolmaster, teacher of children," from Old French pedagoge "teacher of children" (14c.), from Latin paedagogus, from Greek paidagōgos "slave who escorts boys to school and generally supervises them," later "a teacher or trainer of boys," from pais (genitive paidos) "child" (see pedo-) + agōgos "leader," from agein "to lead" (from PIE root *ag- "to drive, draw out or forth, move").

"[N]ow used, generally with a sense of contempt, for a dogmatic and narrow-minded teacher" [Century Dictionary, 1895]; the hostile implications in the word are from at least the time of Pepys (1650s). Related: Pedagogal.