Mentor
Μέντωρ
The friend Odysseus left his son with when he sailed away.
Departing for Troy, Odysseus entrusted the young Telemachus to him.
In the scenes where decisive advice is actually given, it is Athena who appears in Mentor's form.
When the 18th-century French novel The Adventures of Telemachus became a sensation, the name turned into a common word for "teacher."
SourcesHomer, Odyssey