catechumen vs pupil

catechumen and pupil both are nouns.

Word	Noun	Adjective	Verb	Adverb
catechumen	Yes	No	No	No
pupil	Yes	No	No	No

As nouns, pupil is a hypernym of catechumen; that is, pupil is a word with a broader meaning than catechumen:

catechumen: a new convert being taught the principles of Christianity by a catechist
pupil: a learner who is enrolled in an educational institution

Other hypernyms of catechumen include educatee, student.

catechumen (noun)	pupil (noun)
a new convert being taught the principles of Christianity by a catechist	the contractile aperture in the center of the iris of the eye; resembles a large black dot
	a learner who is enrolled in an educational institution
	a young person attending school (up through senior high school)