Pupil (noun)

1. A student in school or college.
2. The dark circular opening in the center of the iris through which light enters the eye.
3. The part of the eye that dilates or constricts to control the amount of light entering the eye.

Origin:

From the latin pupilla, meaning a doll or a small girl, or a small image, or the pupil of the eye.

Examples:

1. The teacher's pupils were well-behaved and hardworking.
2. The pupil of the eye is responsible for adjusting the amount of light that enters the eye.
3. The pupils were asked to complete an assignment.
4. The pupils were dilated by the eye doctor during the examination.
5. The pupils were constricted in bright light to reduce glare.