magnetomotive

The story

1. Ancient GreekΜάγνης (Mágnēs)
2. Ancient Greekμᾰ́γνης (mắgnēs)
3. Old Frenchmagnete
4. Ancient Greekμᾰ́γνης (mắgnēs)
5. Latinmagnēs
6. Middle Englishmagnete
7. Englishmagnet
8. Englishmagnet-
9. Englishmagneto-
10. Anglo-Normanmotif
11. Middle Frenchmotif
12. Proto-Indo-European*m(y)ewh₁-
13. Proto-Indo-European*m(y)owh₁éyeti
14. Proto-Italic*moweō
15. Latinmoveō
16. Latinmōtus
17. Late Latinmōtīvum
18. Middle Englishmotif
19. Englishmotive
20. English todaymagnetomotive

From magneto- + motive.