\ ˈhä How to pronounce ha (audio) \
variants: or

Definition of ha

 (Entry 1 of 3)

used especially to express surprise, joy, or triumph

Definition of ha (Entry 2 of 3)


Definition of HA (Entry 3 of 3)

1 hemagglutinin Different circulating influenza A viruses are identified by referring to two signature proteins on their surfaces. One is hemagglutinin (HA), which has at least 15 known variants, or subtypes.— Jeffery K. Taubenberger et al.
2 hour angle

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Synonyms for ha

Synonyms: Interjection

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Examples of ha in a Sentence

Interjection ha! I was right all along!
Recent Examples on the Web: Interjection Some notes (ha): David’s hands-on look at the new Samsung Galaxy Note 8. Michael Calore, WIRED, "Note to Self," 25 Aug. 2017 First, there's Stick (Scott Glenn), the blind warrior whose organization The Chaste has long served as defenders (ha!) against The Hand. Josh Wigler, The Hollywood Reporter, "'The Defenders': Here's How the Marvel Series Plays Out," 19 Aug. 2017 Jimmy and Harry continued on with the interview after Jimmy came back to life (ha) and all was back to business as usual. Brianna Wiest, Teen Vogue, "Harry Styles Takes Jimmy Fallon's Job In New “Tonight Show” Skit," 20 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ha.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of ha


before the 12th century, in the meaning defined above

History and Etymology for ha


Middle English, from Old English

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Time Traveler for ha

Time Traveler

The first known use of ha was before the 12th century

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Cite this Entry

“Ha.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ha. Accessed 28 Feb. 2020.

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More Definitions for ha

How to pronounce HA (audio)

English Language Learners Definition of ha

used especially to express surprise or a feeling of pleasure that you have when you do something or find out about something
variants: or hah \ ˈhä \

Kids Definition of ha

used to show surprise or joy

Medical Definition of HA

hemagglutinin Seasonal strains … evade our immune systems after vaccination or previous infection by constantly changing the structure of their hemagglutinin (HA) surface protein.— Charles J. Russell, The New England Journal of Medicine, 20 Oct. 2011

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More from Merriam-Webster on ha

Thesaurus: All synonyms and antonyms for ha

Rhyming Dictionary: Words that rhyme with ha

Spanish Central: Translation of ha

Nglish: Translation of ha for Spanish Speakers

Britannica English: Translation of ha for Arabic Speakers

Britannica.com: Encyclopedia article about ha

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