790: pupil Feb 5, 2017

It is not uncommon to have one word have multiple meanings, however semantically unrelated they may seem. The word 'pupil' in English means both a student, and is also the name for a part of the eye. In Latin, the term for a student came from a word meaning 'child' ('boy' or 'girl' depending on the gender'), 'pupus' which evolved into the Old French and Middle English 'pupille' meaning 'orphan'. The feminine form of this word, 'pupa' meant 'girl but it also meant 'little doll'. This gave rise to the meaning of the part of an eye so called for miniature reflection that is faintly visible.

For another word with separate two distinct meanings, see this.