One who instructs in a pedantic or dogmatic manner.
[Middle English pedagoge, from Old French, from Latin paedagōgus, slave who supervised children and took them to and from school, from Greek paidagōgos : paido-, boy; see pedo-1 + agōgos, leader (from agein, to lead; see ag- in Indo-European roots).] ped'a·gogu'ish adj.