birth·​day | \ˈbərth-ˌdā \

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

The data included information like people’s birthdays, relationships, religions, locations, work history, subscriptions, and check-ins. Chavie Lieber, Vox, "Cambridge Analytica used fashion preferences to target people on Facebook," 29 Nov. 2018 Life after loss requires lots of adjustments, especially during the holidays and celebratory days like birthdays. Dixie Lincoln-nichols, SELF, "5 Ways I Learned to Deal With Grief During the Holidays," 21 Nov. 2018 Best of all, the kit drops on Kris Jenner's birthday. Leah Prinzivalli, Allure, "Kylie Jenner Is Releasing a Todd Kraines Lip Kit for Old-School KUWTK Fans," 9 Nov. 2018 Nick Jonas, after only two months of dating Priyanka Chopra, shut down the famed jewelers shop in London on her birthday weekend to give his now-fiancé the same royal treatment. Carrie Goldberg, Harper's BAZAAR, "Priyanka Chopra's Diamond-Filled Dance Party Bridal Shower Was Everything #GOALS," 30 Oct. 2018 While the architects and designers mentioned below may not have actual birthdays that correspond to your zodiac’s dates, their personalities and styles are spot-on matches to each sign’s tropes. Diana Budds, Curbed, "Based on your zodiac sign, what should your Halloween costume be?," 10 Oct. 2018 Corey Tenold, a photographer who’s shot for The New York Times, W magazine, as well as Vogue, and model Ashlee Walker met at her agent’s birthday party in October 2011. Alexandra Macon, Vogue, "This Couple Married at Their Fantasy Location: A 70-Acre Farm in Minnesota," 16 Nov. 2018 The Golden Globes will be her ultimate birthday party celebration. Jessica Radloff, Glamour, "5 Things to Know About Idris Elba's Daughter, Isan, the 2019 Golden Globes Ambassador," 16 Nov. 2018 The Weeknd The musician subtly shaded ex Selena Gomez by holding hands with Justin's ex, Yovanna Ventura, all night during French Montana's birthday party, a source told Us Weekly. Stacey Grant, Seventeen, "18 Celebs Who Threw Massive Amounts of Shade at Their Exes," 17 Oct. 2018

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

10 Dec 2018

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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 \

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

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