uneconomical

The story

1. Proto-Indo-European*né
2. Proto-Indo-European*n̥-
3. Proto-Germanic*un-
4. Proto-West Germanic*un-
5. Old Englishun-
6. Middle Englishun-
7. Englishun-
8. Proto-Indo-European*weyḱ-
9. Proto-Indo-European*wóyḱos
10. Proto-Hellenic*wóikos
11. Ancient Greekϝοῖκος (woîkos)
12. Ancient Greekοἶκος (oîkos)
13. Proto-Indo-European*nem-
14. Proto-Indo-European*németi
15. Proto-Hellenic*némō
16. Ancient Greekνέμω (némō)
17. Ancient Greekνόμος (nómos)
18. Ancient Greekοἰκονόμος (oikonómos)
19. Ancient Greekοἰκονομικός (oikonomikós)
20. Latinoeconomicus
21. Old Frenchiconomike
22. Middle Englishiconomique
23. Middle Englisheconomike, iconomique
24. Englisheconomic
25. Proto-Indo-European*h₂el-
26. Proto-Indo-European*h₂élisder.?
27. Englisheconomical
28. English todayuneconomical

From un- + economical.