birth·​day ˈbərth-ˌdā How to pronounce birthday (audio)
: the day of a person's birth
: a day of origin
: an anniversary of a birth
her 21st birthday

Examples of birthday in a Sentence

Her birthday is September 30th. Today is his 21st birthday. The company just celebrated its 50th birthday.
Recent Examples on the Web To celebrate his 42nd birthday on June 21, the Prince of Wales showed off his dance moves at Taylor Swift's concert in London with his two eldest children, Prince George and Princess Charlotte. Can't get enough of PEOPLE's Royals coverage? Stephanie Petit, Peoplemag, 27 June 2024 The annual Fourth of July race began 19 years ago without planning or concern for safety: Three young friends decided to celebrate America’s birthday by hurling themselves down a steep San Clemente street in office chairs. Hannah Fry, Los Angeles Times, 27 June 2024 From here, the goings on are all too ordinary — and mundane: Clinic employees demonstrate procedures, replace batteries in clocks, hold workshops, sterilize equipment, check patients in for appointments and celebrate each other’s birthdays. Kristen Rogers, CNN, 26 June 2024 The family celebrated Sonny’s first birthday on June 20. Dina Kaur, The Arizona Republic, 26 June 2024 See all Example Sentences for birthday 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'birthday.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

14th century, in the meaning defined at sense 2

Time Traveler
The first known use of birthday was in the 14th century

Dictionary Entries Near birthday

Cite this Entry

“Birthday.” Dictionary, Merriam-Webster, Accessed 14 Jul. 2024.

Kids Definition


birth·​day ˈbərth-ˌdā How to pronounce birthday (audio)
: the day or anniversary of one's birth
: the day or anniversary of a beginning

More from Merriam-Webster on birthday

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