unmystic

The story

1. Proto-Indo-European*né
2. Proto-Indo-European*n̥-
3. Proto-Germanic*un-
4. Proto-West Germanic*un-
5. Old Englishun-
6. Middle Englishun-
7. Englishun-
8. Proto-Indo-European*mewH-
9. Proto-Indo-European*mewH-ye-
10. Ancient Greekμῡ́ω (mū́ō)
11. Ancient Greekμῠέω (mŭéō)
12. Ancient Greekμῠ́στης (mŭ́stēs)
13. Ancient Greekμῠστῐκός (mŭstĭkós)
14. Latinmysticus
15. Old Frenchmistique
16. Englishmystic
17. English todayunmystic

From un- + mystic.