goodbye

What it means

1. Farewell; a formula used to another person or persons when the speaker, writer, or person addressed is departing.

   Goodbye! - Goodbye, Anna.

   2016, VOA Learning English (public domain)

   Synonyms: adieu, farewell, bye, bye-bye, catch you later, mind how you go, ya, you

In a sentence

Goodbye! - Goodbye, Anna.

2016, VOA Learning English (public domain)

Where it comes from

1. Proto-Indo-European*ǵʰew-
2. Proto-Indo-European*ǵʰutós?
3. Proto-Germanic*gudą
4. Proto-West Germanic*god
5. Old Englishgod
6. Middle Englishgod
7. Middle EnglishGod
8. EnglishGod
9. Proto-Indo-European*bʰuH-
10. Proto-Indo-European*bʰuHyétider.?
11. Proto-Germanic*beuną
12. Proto-West Germanic*beun
13. Old Englishbēon
14. Middle Englishbeen
15. Englishbe
16. Proto-Indo-European*dwóh₁
17. Proto-Indo-European*dwi-
18. Proto-Indo-European*wí
19. Proto-Indo-European*wíteros
20. Proto-Indo-European*wíterom
21. Proto-Germanic*wiþrą
22. Proto-West Germanic*wiþr
23. Old Englishwiþerclip.
24. Old Englishwiþ
25. Middle Englishwiþ
26. Englishwith
27. Proto-Indo-European*yúHs
28. Proto-Indo-European*uswé
29. Proto-Indo-European*uswís
30. Proto-Germanic*izwiz
31. Proto-West Germanic*iwwiz
32. Old Englishēow
33. Middle Englishyow
34. Englishyou
35. Englishgoodinflu.
36. Englishgoodbye

From earlier goodby, Godby, Godby'e, Godbwye, God b'w'y, God bwy yee, God buy you, God be wi' you, each a progressively shorter contraction of God be with ye or God be with you. Note the change of God to good by confusion with good morning, good night, etc. Modernly analysed as good + bye.