megabit

The story

1. Proto-Indo-European*méǵh₂s
2. Proto-Hellenic*mégas
3. Ancient Greekμέγᾰς (mégăs)
4. Englishmega-
5. Proto-Indo-European*dwóh₁
6. Proto-Indo-European*trísinflu.
7. Proto-Indo-European*dwís
8. Proto-Italic*dwis
9. Proto-Italic*dwiznos
10. Latinbīnus
11. Late Latinbīnāriu
12. Middle Englishbinarie
13. Englishbinary
14. Proto-Indo-European*deyḱ-der.?
15. Latindigitus
16. Middle Englishdigit
17. Englishdigit
18. Englishbinary digitabbr.
19. Englishbitinflu.
20. Englishbit
21. English todaymegabit

From mega- + bit.