birthday

American  

[burth-dey] / ˈbɜrθˌdeɪ /

noun

1. the anniversary of a birth.

2. the day of a person's birth.

3. a day marking or commemorating the origin, founding, or beginning of something.

4. the festivities or celebration marking such a day or anniversary.

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birthday British  

/ ˈbɜːθˌdeɪ /

noun

1. 1. an anniversary of the day of one's birth

   2. ( as modifier )

      birthday present

2. the day on which a person was born

3. any anniversary

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Etymology

Origin of birthday

Middle English word dating back to 1350–1400; birth, day

Example Sentences

But the moment was bittersweet for him as Monday was also the birthday of his father Vitaly.

From BBC

The final straw: Everyone in the group was invited to a child’s birthday party except Lu and her kid.

From The Wall Street Journal

In baseball, players generally see their performance peak in their mid-20s and begin to decline not long after their 30th birthday.

From The Wall Street Journal

The timing, which the report said was subject to change, also aligns closely with June 28, Musk's 54th birthday.

From Barron's

The account will be locked until the child’s 18th birthday, giving the money a chance to compound.

From MarketWatch