biofluorescent

The story

1. Proto-Indo-European*gʷeyh₃-
2. Ancient Greekβῐ́ος (bĭ́os)
3. Ancient Greekβῐο- (bĭo-)
4. Englishbio-
5. Proto-Indo-European*bʰel-
6. Proto-Indo-European*bʰlewH-
7. Proto-Indo-European*bʰluH-yé-ti?
8. Latinfluō
9. Latinfluor
10. Englishfluor
11. Englishfluorite
12. Middle Low Germanspar
13. Old Englishspærstān
14. Middle Englishsparston
15. Englishsparstonebf.
16. Englishspar
17. Englishfluorspar
18. Englishfluorescencebf.
19. Englishfluoresce
20. Englishfluorescent
21. English todaybiofluorescent

From bio- + fluorescent.