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

Bold, 28, spoke to Newsweek about her parents' remarriage and her mother's recent birthday surprise, which embodied their enduring love. —Maria Morava, MSNBC Newsweek, 28 June 2025

So 32 minus 7 is 25, my sister’s favorite number is 25, her birthday is on the 25th of July, also I got drafted in 2025 and on June 25. —Anthony Chiang, Miami Herald, 27 June 2025

The first time everyone was together was at my 60th birthday. —Rick Porter, HollywoodReporter, 27 June 2025

Wear it with your favorite jewelry, a cute purse, and ballet flats, if you’re headed to date night or a birthday party. —Isabel Garcia, People.com, 27 June 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