indoctrinator

transitive verb indoctrinated, indoctrinating

1. to instruct in, or imbue with, doctrines, theories, or beliefs, as of a sect
2. to instruct; teach

Origin: prob. (after ML doctrinatus, pp. of doctrinare, to instruct < L doctrina) < ME endoctrinen < OFr endoctriner: see in- & doctrine