trainiac

The story

1. Proto-Indo-European*dʰregʰ-der.?
2. Latintrahere
3. Vulgar Latin*tragīnāre
4. Old Frenchtraïner
5. Old Frenchtrain
6. Middle Englishtrayne
7. Englishtrain
8. Proto-Indo-European*men-
9. Proto-Indo-European*mn̥yétor
10. Proto-Hellenic*məňňómai
11. Ancient Greekμαίνομαι (maínomai)
12. Ancient Greekμᾰνῐ́ᾱ (mănĭ́ā)
13. Ancient Greekμανιακός (maniakós)
14. Late Latinmaniacu
15. Frenchmaniaque
16. Englishmaniac
17. English todaytrainiac

Blend of train + maniac.