inkless

The story

1. Proto-Indo-European*h₁én
2. Ancient Greekἐν (en)
3. Ancient Greekἐν- (en-)
4. Proto-Indo-European*keh₂w-
5. Proto-Hellenic*káwyō
6. Ancient Greekκαίω (kaíō)
7. Ancient Greekκαυστός (kaustós)
8. Ancient Greekἔγκαυστον (énkauston)
9. Late Latinencaustum
10. Old Frenchenque
11. Middle Englishynke
12. Englishink
13. Proto-Indo-European*lewh₁-
14. Proto-Indo-European*lewHs-
15. Proto-Germanic*leusaną
16. Proto-Germanic*lausaz
17. English todayinkless

From ink + -less.