deponer

The story

1. Proto-Indo-European*de
2. Proto-Indo-European*déh₁
3. Proto-Italic*dē
4. Latindē
5. Latindē-
6. Proto-Indo-European*h₂ep
7. Proto-Indo-European*h₂epó
8. Proto-Indo-European*h₂pó
9. Proto-Italic*po
10. Proto-Indo-European*teḱ-
11. Proto-Indo-European*tḱéytibf.
12. Proto-Indo-European*tḱey-
13. Proto-Indo-European*tḱinéti
14. Proto-Italic*sinō
15. Proto-Italic*pozinō
16. Latinpōnō
17. Latindēpōnō
18. Englishdepone
19. English todaydeponer

From depone + -er.