bye : Idioms & Phrases

• adverb introducing a different topic; in point of fact
  incidentally; by the way; apropos.
  
  • incidentally, I won't go to the party

WordNet

• in passing; by way of digression; apropos to the matter in hand. Written also by the by.

Webster 1913

• noun a farewell remark
  good-by; adieu; adios; so long; cheerio; arrivederci; sayonara; auf wiedersehen; goodbye; bye-bye; goodby; bye; good day; au revoir.
  
  • they said their good-byes

WordNet

• noun a special election between regular elections
  by-election.
  

WordNet

• noun a farewell remark
  good-by; adieu; adios; so long; cheerio; arrivederci; sayonara; auf wiedersehen; goodbye; bye-bye; goodby; bye; good day; au revoir.
  
  • they said their good-byes

WordNet

Good`-by", Good`-bye" noun ∨ interjection (Also<

• Good-by
• Good-bye

)

Etymology

A contraction of God be with ye (God be w&icr; ye, God bw' ye, God bwye).

Definitions

1. Farewell; a form of address used at parting. See the last Note under By, prep. Shak.

Webster 1913