larper

The story

1. Proto-Indo-European*h₂en-
2. Proto-Germanic*an
3. Proto-West Germanic*ana
4. Old Englishon
5. Proto-Indo-European*leyp-
6. Proto-Germanic*lībaną
7. Proto-Germanic*lībą
8. Proto-West Germanic*līb
9. Old Englishlīf
10. Old Englishlīfe
11. Old Englishon līfe
12. Middle Englishalyve
13. Englishaliveclip.
14. Englishlive
15. Proto-Indo-European*h₂eǵ-
16. Proto-Indo-European*h₂éǵeti
17. Proto-Italic*agō
18. Latinagō
19. Latināctum
20. Latināctiō
21. Old Frenchaucion
22. Middle Englishaccioun
23. Englishaction
24. Englishlive-action
25. Proto-Indo-European*Hreth₂-
26. Proto-Indo-European*Hróth₂eh₂
27. Proto-Italic*rotā
28. Latinrota
29. Medieval Latinrollu
30. Old Frenchrole
31. Middle Frenchrolle
32. Frenchrôle
33. Englishrole
34. Proto-West Germanic*plehan
35. Old Englishpleġan
36. Proto-West Germanic*plegō
37. Proto-West Germanic*plegōn
38. Old Englishplegian
39. Middle Englishpleyen
40. Proto-West Germanic*plegō
41. Old Englishplega
42. Middle Englishpleye
43. Englishplay
44. Englishroleplay
45. EnglishLARP
46. English todayLARPer

From LARP + -er.