bye

bye — exclamation

1. a friendly word you say when you are leaving someone or ending a phone call.

1.exclamationA1
Definition

a friendly word you say when you are leaving someone or ending a phone call.

Example

Bye, Marcus! See you at the party tonight.

casual leave-taking with a name

Lina waved from the train window and shouted, 'Bye, Mum!'

scene-setting around a parting

Common collocations
  • say bye
  • wave bye
  • bye for now
  • bye-bye
Synonyms
  • goodbye

    slightly more neutral; works in both spoken and written contexts

  • see you

    very informal; suggests you expect to meet again soon

  • farewell

    literary or solemn; used for long or final partings

  • cheerio

    British informal; sounds cheerful and a bit old-fashioned

Antonyms
  • hello

    the matching greeting when meeting someone

  • hi

    the casual matching greeting

Usage Note

Informal register; in formal letters or speeches use 'goodbye' or 'farewell' instead. Often doubled as 'bye-bye' when speaking to small children or when waving someone off.

Common Mistakes

Dear Sir, Bye.
Dear Sir, Yours sincerely,
'bye' is too casual to close a formal letter or email.

bye — noun

Word family

  • bye-bye
    exclamationA1
  • goodbye
    exclamationA1

Synonym discussion

Sense: exclamation/1

All five words mark the moment of parting, but they sit on different rungs of formality and warmth. 'Bye' and its doubled form 'bye-bye' are the everyday choice in speech and casual messages — short, friendly, and slightly affectionate, especially with children. 'Goodbye' is one step more neutral and works in writing as well as speech, including polite professional contexts. 'See you' (or 'see ya') is the most informal of all and signals an expected next meeting, so avoid it after a final separation. 'Farewell' is literary or ceremonial and now sounds dramatic in everyday talk; reserve it for speeches, songs, or long absences. 'Cheerio' is a cheerful British alternative that older speakers still use. So you might end a phone call with a parent by saying 'Bye, love you,' close a customer email with 'Goodbye and thank you,' and toast a retiring colleague with 'Farewell, and good luck.'

bye ↗goodbye ↗see youfarewellcheerio

Common collocations

Nouns

  • bye-bye
  • first-round bye

Phrases

  • say bye
  • wave bye
  • kiss someone bye

Prepositions

  • bye for now
  • bye to [someone]

Etymology

Old EnglishMiddle EnglishModern English

The exclamation 'bye' is a shortened form of 'goodbye', which itself grew out of the older parting phrase 'God be with ye' over several centuries of speech, gradually contracting as people said it faster. The doubled form 'bye-bye' appeared as a soothing nursery word in the 1700s. The sports noun is unrelated in origin: it comes from the preposition 'by', meaning 'past' or 'aside', and was first used in cricket and then in tournament play to describe a player or run that goes 'past' the usual contest.