birthday

noun

birth·​day ˈbərth-ˌdā 

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

Instead of Gabrielle making the birthday cakes, her siblings and parents teamed up to surprise her with a spread of six homemade desserts—each one crafted by a different family member. —Dan Perry, Newsweek, 28 Feb. 2025

The 2024 season was a struggle, though, after Ward’s daughter — Amani Joy — passed away following a prolonged battle with heart issues just before her second birthday. —Rob Reischel, Forbes, 28 Feb. 2025

Expect even more excitement this year when Will Smith shows up for Chris Rock’s 75th birthday tribute. —Steven Zeitchik, The Hollywood Reporter, 28 Feb. 2025

The majority of the patients die before their 30th birthday. —Dr. Bilal Hameed, Hartford Courant, 27 Feb. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 2

Phrases Containing birthday

• birthday suit

Rhymes for birthday

• airway
• allay
• archway
• array
• ashtray
• astray
• aue
• away
• ballet
• belay
• beltway
• beret

Kids Definition

birthday

noun

birth·​day ˈbərth-ˌdā 

1

: the day or anniversary of one's birth

2

: the day or anniversary of a beginning