economical

The story

1. Proto-Indo-European*weyḱ-
2. Proto-Indo-European*wóyḱos
3. Proto-Hellenic*wóikos
4. Ancient Greekϝοῖκος (woîkos)
5. Ancient Greekοἶκος (oîkos)
6. Proto-Indo-European*nem-
7. Proto-Indo-European*németi
8. Proto-Hellenic*némō
9. Ancient Greekνέμω (némō)
10. Ancient Greekνόμος (nómos)
11. Ancient Greekοἰκονόμος (oikonómos)
12. Ancient Greekοἰκονομικός (oikonomikós)
13. Latinoeconomicus
14. Old Frenchiconomike
15. Middle Englishiconomique
16. Middle Englisheconomike, iconomique
17. Englisheconomic
18. Proto-Indo-European*h₂el-
19. Proto-Indo-European*h₂élisder.?
20. English todayeconomical

From economic + -al.