cat·e·che·sis (kāt'ĭ-kē'sĭs) n.
pl.cat·e·che·ses (-sēz) Oral instruction given to catechumens.
[Late Latin catēchēsis, from Greek katēkhēsis, oral instruction, from katēkhein, to teach by word of mouth; see catechize.] cat'e·chet'i·cal (-kět'ĭ-kəl) adj.