pupil vs younker

pupil and younker both are nouns.

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

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

Other hypernyms of pupil include spring chicken, young person, youth.

pupil (noun)	younker (noun)
the contractile aperture in the center of the iris of the eye; resembles a large black dot	a young person (especially a young man or boy)
a learner who is enrolled in an educational institution
a young person attending school (up through senior high school)