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.
Kotb’s Easter Sunday doubled as a birthday celebration for her mother. — Diane J. Cho, PEOPLE, 9 Aug. 2026 Heming Willis told Kotb that her husband's condition initially left her feeling guilty about celebrating her recent 50th birthday. — Charlie Carballo, USA Today, 8 Aug. 2026 Even away from the field — his youngest daughter’s birthday was Thursday. — Meghan Montemurro, Chicago Tribune, 8 Aug. 2026 Trout, who turned 35 on Friday, hit a home run on his birthday for the sixth time in his 16 MLB seasons. — Los Angeles Times, 8 Aug. 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 12 Aug. 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

More from Merriam-Webster on birthday

Nglish: Translation of birthday for Spanish Speakers

Last Updated: - Updated example sentences
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