diphenyl

The story

1. Proto-Indo-European*dwóh₁
2. Proto-Indo-European*dwi-
3. Proto-Hellenic*dwi-
4. Ancient Greekδῐ- (dĭ-)
5. Latindi-
6. Englishdi-
7. Proto-Indo-European*bʰeh₂-
8. Proto-Indo-European*bʰh₂nyéti
9. Proto-Hellenic*pʰáňňō
10. Ancient Greekφαίνω (phaínō)
11. Frenchphéno-
12. Proto-Indo-European*swel-der.?
13. Ancient Greekῡ̔́λη (hū́lē)
14. Frenchphényle
15. Englishphenyl
16. English todaydiphenyl

From di- + phenyl.