superoverwhelming

The story

1. Proto-Indo-European*úp
2. Proto-Indo-European*upér
3. Proto-Italic*super
4. Latinsuper
5. Latinsuper-
6. Englishsuper-
7. Proto-Indo-European*upér
8. Proto-Germanic*uber
9. Old Englishofer-
10. Middle Englishover-
11. Proto-Indo-European*kʷelp-
12. Proto-Germanic*kʷolpós
13. Proto-Germanic*hwalbazder.?
14. Proto-Indo-European*kʷelp-
15. Proto-Germanic*kʷólpo-
16. Proto-Germanic*hwalbąder.?
17. Old Englishhwealf
18. Old English*hwealfnian
19. Old English*hwealmnian?
20. Middle Englishwhelmen
21. Middle Englishoverwhelmen
22. Englishoverwhelm
23. Englishoverwhelming
24. English todaysuperoverwhelming

From super- + overwhelming.