indoctrination (n.)

formerly also endoctrinate, 1620s, "to teach," formed as if from Latin (but there seems to have been no word *indoctrinare), perhaps modeled on French endoctriner or extended from earlier (now obsolete) verb indoctrine, endoctrine, "to instruct" (mid-15c.); see in- (2) "in" + doctrine + -ate (2)). Meaning "to imbue with an idea or opinion" first recorded 1832. Related: Indoctrinated; indoctrinating.