birth·​day | \ ˈbərth-ˌdā How to pronounce birthday (audio) \

Definition of birthday

1a : 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.
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Recent Examples on the Web

But today is RBG’s 86th birthday, and thus there is special cause to sing her praises. Marley Marius, Vogue, "Happy Birthday, Ruth Bader Ginsberg! An Ode to the Supreme Court Justice and Her Iconic Accessorizing," 15 Mar. 2019 Fashion Nova has made no secret of its quick and cheap dupes of the Kardashian and Jenner’s outfit in the past, even once recreating all the looks the sisters wore to Kylie’s birthday party. Alyssa Hardy, Teen Vogue, "Imitation In Fashion is a Huge Problem, But It's Probably Not Going Anywhere," 13 Mar. 2019 Despite reaching its 50th birthday this week, Boeing has had a hard time delivering the once-vaunted jet, as airlines continuously seek smaller, fuel-efficient aircraft. Sam Blum, Popular Mechanics, "Airbus to Stop Production of the Colossal A380 as Airlines Transition to Smaller Planes," 14 Feb. 2019 That changed on one of my birthdays in the mid '90s when the Sony PlayStation came out. Ron Amadeo, Ars Technica, "Our favorite (and least favorite) tech of 2018," 26 Dec. 2018 McGonagall’s birthday had previously been worked out by fans at the Harry Potter wiki to be in 1935, eight years after Crimes takes place. Chaim Gartenberg, The Verge, "The biggest unanswered questions from Fantastic Beasts: The Crimes of Grindelwald," 26 Nov. 2018 In honor of Sara Sampaio’s birthday, NYC gym Dogpound raised a glass—er, dumbbell—to toast the Victoria’s Secret model’s 27th year. Jenny Mccoy, SELF, "Why Sara Sampaio's Dumbbell Raise Exercise Is Great for Strengthening Your Shoulders," 23 July 2018 Shortly before her wedding to Prince Harry in 2018, Meghan attended the Queen's 92nd birthday in a sleek navy blue Stella McCartney sheath dress whose sole embellishment was the cape cut. Roxanne Adamiyatt, Town & Country, "How to Wear a Cape Like Kate Middleton and Meghan Markle," 28 Feb. 2019 For Jordyn's 18th birthday in 2015, Kylie reportedly gave her friend a $70,000 Mercedes convertible. Katherine J. Igoe, Marie Claire, "Estimating Jordyn Woods' Net Worth From Her Kardashian Collaborations," 21 Feb. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'birthday.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of birthday

14th century, in the meaning defined at sense 2

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Statistics for birthday

Last Updated

19 Mar 2019

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Time Traveler for birthday

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

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More Definitions for birthday



English Language Learners Definition of birthday

: the day when someone was born or the anniversary of that day
: the day when something began


birth·​day | \ ˈbərth-ˌdā How to pronounce birthday (audio) \

Kids Definition of birthday

1 : the day or anniversary of someone's birth
2 : a day of beginning Our town just celebrated its 150th birthday.

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More from Merriam-Webster on birthday

Rhyming Dictionary: Words that rhyme with birthday

Spanish Central: Translation of birthday

Nglish: Translation of birthday for Spanish Speakers

Britannica English: Translation of birthday for Arabic Speakers

Comments on birthday

What made you want to look up birthday? Please tell us where you read or heard it (including the quote, if possible).


to boil down or concentrate

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