troonism

The story

1. Proto-Indo-European*terh₂-
2. Proto-Indo-European*térh₂t
3. Proto-Indo-European*tr̥h₂ónts
4. Proto-Indo-European*tr̥h₂n̥ts
5. Proto-Italic*trāns
6. Proto-Italic*trāns-
7. Latintrans-
8. Englishtrans-
9. Proto-Indo-European*ǵenh₁-
10. Proto-Indo-European*ǵénh₁os
11. Proto-Italic*genos
12. Latingenus
13. Old Frenchgendre
14. Middle Englishgendre
15. Englishgender
16. Englishtransgender
17. Proto-Indo-European*dʰeǵʰ-
18. Proto-Indo-European*dʰéǵʰōm
19. Proto-Indo-European*ǵʰmṓ
20. Proto-Germanic*gumô
21. Proto-West Germanic*gumō
22. Old Englishguma
23. Middle Englishgone?
24. Englishgooney
25. Englishgoon
26. Englishtroon
27. English todaytroonism

From troon (“transgender person”) + -ism.