birthday

noun

birth·​day ˈbərth-ˌdā How to pronounce birthday (audio)
1
a
: the day of a person's birth
b
: a day of origin
2
: 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The tension follows the women to Courtney’s event celebrating her husband’s birthday, where the real entertainment for the evening was Tia and Gizelle lacing stepping in the ring. — Shamira Ibrahim, Vulture, 26 Oct. 2026 In the spirit of B-movie icons like Roger Corman, the film was shot in four days for $40,000 in order to celebrate Chris LaMartina’s 40th birthday. — William Earl, Variety, 26 Oct. 2026 On a recent weekend some of his El Paso classmates and their mothers crossed the bridge to celebrate his 11th birthday on the Mexican side. — Angela Kocherga, NPR, 26 Oct. 2026 On America’s birthday, at least, Kushner’s mood was persuasively statesmanlike. — Lauren Collins, New Yorker, 26 Oct. 2026 See All Example Sentences for birthday

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

Phrases Containing birthday

Rhymes for birthday

See All Rhymes for birthday

Browse Nearby Words

birth date
birthday
birthday cake
See all Nearby Words

Cite this Entry

“Birthday.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/birthday. Accessed 27 Oct. 2026.

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Kids Definition

birthday

noun
birth·​day ˈbərth-ˌdā How to pronounce birthday (audio)
1
: the day or anniversary of one's birth
2
: the day or anniversary of a beginning
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