means Either a child being taught by a teacher, or the dark adjustable opening at the center of your eye that lets light in.

from From Latin 'pupilla,' a 'little doll' — the diminutive of 'pupa,' meaning girl or doll. Why the eye? Because when you peer into someone's pupil up close, you see a tiny reflection of yourself, doll-sized. The same Latin word also meant 'orphan' or 'ward,' a small one under another's care — which is how 'pupil' came to mean a student. So both senses share a single root: the little one, whether mirrored in an eye or seated at a desk.