phosphatidylserine

The story

1. Proto-Indo-European*bʰeh₂-
2. Proto-Indo-European*bʰéh₂os
3. Proto-Hellenic*pʰáwos
4. Ancient Greekφᾰ́ος (phắos)
5. Ancient Greekφῶς (phôs)
6. Proto-Indo-European*bʰer-
7. Proto-Indo-European*bʰéreti
8. Proto-Hellenic*pʰérō
9. Ancient Greekφέρω (phérō)
10. Ancient Greekφωσφόρος (phōsphóros)
11. Latinphōsphorus
12. Frenchphosphore
13. Frenchphosphate
14. Englishphosphate
15. Proto-Indo-European*dʰeh₁-
16. Englishphosphatide
17. Englishphosphatidate
18. Proto-Indo-European*swel-der.?
19. Ancient Greekῡ̔́λη (hū́lē)
20. Englishphosphatidyl
21. Old Chinese絲 (*sə)der.?
22. Ancient Greekσήρ (sḗr)
23. Ancient Greekσηρῐκός (sērĭkós)
24. Latinsēricus
25. Englishserine
26. English todayphosphatidylserine

From phosphatidyl + serine.