"Mentee"

I'm often tempted to use "mentee" to describe someone who is being mentored, but "mentee" is not an actual word. Mentor was the friend Odysseus entrusted to educate his son, Telemachus. This conundrum came up at work a few years ago. How does one refer to the person you are mentoring? Once we discovered mentee wasn't a word, we learned that Telemachus was the original "one who is being mentored." However, "Telemachus" as a substitute for "one who is being mentored" never quite took off as part of our office lexicon.