zoological

The story

1. Proto-Indo-European*gʷeyh₃-
2. Proto-Indo-European*gʷyéh₃-w-os
3. Proto-Hellenic*d͏̌ōwós
4. Ancient Greekζωός (zōós)
5. Ancient Greekζώῐ̈ον (zṓĭ̈on)
6. Ancient Greekζῷον (zōîon)
7. Proto-Indo-European*leǵ-
8. Proto-Indo-European*lóǵos
9. Proto-Hellenic*lógos
10. Ancient Greekλόγος (lógos)
11. Englishzoology
12. Proto-Indo-European*h₂el-
13. Proto-Indo-European*h₂élisder.?
14. English todayzoological

From zoology + -ical.