'catechumenal' originates from Late Latin 'catechumenus' and ultimately from Greek 'katēchoumenos', meaning 'one being instructed' (from the verb 'katēcheō' 'to instruct orally').

'catechumenal' developed via Late Latin 'catechumenus' and ecclesiastical Latin usage into Middle English forms related to the church's catechumenate, eventually becoming the modern English adjective 'catechumenal'.

Initially it referred directly to a 'catechumen' (a person being instructed); over time an adjectival sense developed meaning 'relating to catechumens or their instruction'.