propaedeutic (n.)youdaoicibaDictYouDict[propaedeutic 词源字典]
1798, from Greek propaideuein "to teach beforehand," from pro- (see pro-) + paideuein "to teach," which is related to the root of pedagogue. From 1849 as an adjective.[propaedeutic etymology, propaedeutic origin, 英语词源]