pupil

Etymology 1

From Middle English pupille, from Anglo-Norman pupille (“orphan”), from Latin pūpillus (“orphan, minor”), variant of pūpulus (“little boy”), from pūpus (“child, boy”).

noun

1. (dated outside UK) A learner at a school under the supervision of a teacher.
   The Pupil after his Pupillarity, had granted a Diſcharge to one of the Co-tutors, which did extinguiſh the whole Debt of that Co-tutor, and conſequently of all the reſt, they being all correi debendi, lyable by one individual Obligation, which cannot be Diſcharged as to one, and ſtand as to all the reſt. 1668 December 19, James Dalrymple, “Mr. Alexander Seaton contra Menzies” in The Deciſions of the Lords of Council & Seſſion I (Edinburgh, 1683), page 575
   Imagine a country where children do nothing but play until they start compulsory schooling at age seven. Then, without exception, they attend comprehensives until the age of 16. Charging school fees is illegal, and so is sorting pupils into ability groups by streaming or setting. 2013-07-19, Peter Wilby, “Finland spreads word on schools”, in The Guardian Weekly, volume 189, number 6, page 30
2. One who studies under supervision of a renowned expert in their field.
   Plato was Socrates' pupil, and in turn Aristotle was Plato's pupil.
3. (law, obsolete) An orphan who is a minor and under the protection of the state.

Etymology 2

From Middle English pupille, from Old French pupille, from Latin pūpilla (“pupil; little girl, doll”), named because of the small reflected image seen when looking into someone's eye.

noun

1. (anatomy) The hole in the middle of the iris of the eye, through which light passes to be focused on the retina.
   There are sharks with round pupils, sharks with slitlike pupils, and some with pupils that expand and contract with the amount of light available. As unimpressive as this might sound to people who are used to having their pupils dilate and contract regularly, realize that no bony fish has this modification of the eye. 1983, Richard Ellis, The Book of Sharks, Knopf, page 29
2. (zoology) The central dark part of an ocellated spot.