noun
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an anniversary of the day of one's birth
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( as modifier )
birthday present
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the day on which a person was born
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any anniversary
Etymology
Origin of birthday
Middle English word dating back to 1350–1400; see origin at birth, day
Explanation
Your birthday is the day of your birth! It’s the yearly anniversary that marks the day you were born. Not everyone celebrates, but a birthday is a good excuse for a party and cake. You can use birthday both to refer to the specific day of a baby's birth, and the annual marking of that day throughout the years that follow. Sometimes people talk about the birthday of a country, group, or even a building: "It's the art museum's fiftieth birthday next year." The Old English byrddæg originally referred to the celebration of a king or saint's birth, but over the years it was extended to include everyone.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Salaam claimed that in September 2021, he attended a private birthday party for Will Smith at the Regency Calabasas Commons.
From Los Angeles Times • Apr. 24, 2026
One of them, Sylvia Beach, published “Ulysses” from her bookshop, Shakespeare and Company, on his 40th birthday in 1922.
From The Wall Street Journal • Apr. 24, 2026
It was on Naiping Hou’s May 3 birthday that his son began to suspect someone else was controlling his father’s phone.
From Los Angeles Times • Apr. 24, 2026
She celebrated her 97th birthday with a recital at Lebanon Valley College, Pennsylvania; and returned to Decca in 2022 to record what would become her final album.
From BBC • Apr. 23, 2026
Ana knows it’s my birthday, but no one else does because it feels weird to announce.
From "The Tenth Mistake of Hank Hooperman" by Gennifer Choldenko
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.