retentive (adj.)youdaoicibaDictYouDict[retentive 词源字典]
late 14c., "able to hold or keep" (mental or physical), from Old French retentif, from Medieval Latin retentivus, from past participle stem of Latin retinere (see retain). Related: Retentively; retentiveness.[retentive etymology, retentive origin, 英语词源]