catechismyoudaoicibaDictYouDict
catechism: [16] Etymologically, catechism is ‘teaching by the spoken word’. It is a derivative of catechize [15], which comes ultimately from the Greek verb katēkhein, a compound formed from the prefix katá- ‘thoroughly’ and the verb ēkhein ‘sound, resound’ (related to English echo). Thus originally to ‘catechize’ someone was literally to ‘din’ instruction into them, hence ‘instruct orally’. The word came into English via a later ecclesiastical Greek derivative katēkhízein and Latin catēchīzāre.
=> echo
catechism (n.)youdaoicibaDictYouDict
c. 1500, "instruction in Christian principles," also "elementary question-and-answer book of religious instruction," from French catéchisme (14c.) and directly from Church Latin catechismus "book of instruction," from Greek katekhismos, from katekhizein "to teach orally" (see catechize). Related: Catechismal.