Ecclesiastical. a person under instruction in the rudiments of Christianity, as in the early church; a neophyte.
2.
a person being taught the elementary facts, principles, etc., of any subject.
Origin: 1325–75; < LL catēchūmenus < Gk katēchoúmenos (one who is) being taught orally, equiv. to katēche-, s. of katēcheîn to teach orally (see catechist) + -omenos middle prp. suffix; r. ME cathecumyn < MF cathecumine < LL, as above