mentor

The word 'mentor' originates from the Ancient Greek name 'Méntōr', a character in Homer's epic poem the Odyssey. In the story, Mentor was a trusted friend of Odysseus, entrusted with the education and guidance of Odysseus's son, Telemachus. This literary association imbued the name with the sense of a wise and faithful counselor. Through Latin and later French, the proper name entered English in the 18th century and was generalized into a common noun and verb, shedding its capital letter but retaining its core meaning of experienced guidance.

The word is a simplex loanword. It entered English as a proper name from Greek mythology via Latin and French, and later became a common noun. It is not productively formed from separable English morphemes.