Etymology

From Latin catēchīzō ‎(“I instruct in religion; I catechize”), from Ancient Greek κατηχίζω ‎(katēkhízō, “I instruct orally”), from κατηχέω ‎(katēkhéō, “I resound, instruct orally”), from κατά ‎(katá, “down”) + ἠχή ‎(ēkhḗ, “sound, noise”).