noun
-
-
an anniversary of the day of one's birth
-
( as modifier )
birthday present
-
-
the day on which a person was born
-
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.
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
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
The image was shared on royal social media accounts by Prince William and Catherine who wrote: "Happy birthday, Louis! 8 today!" followed by a red balloon emoji.
From BBC • Apr. 23, 2026
Repackaged, deluxe paperback editions of the other titles in the “Patternist” series — “Patternmaster,” “Mind of My Mind,” “Wild Seed” and “Clay’s Ark” — will be released June 23, the day after Butler’s birthday.
From Los Angeles Times • Apr. 23, 2026
For today was the shop’s one hundredth birthday.
From "The Hiding Place" by Corrie ten Boom
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.
