The woman who gives birth to a child (not necessarily the genetic mother)

(idiomatic, often humorous) Nakedness, unclothed skin; an exposure of a human's natural anatomy without clothing. / Used other than figuratively or idiomatically: see birthday, suit.

(cryptography) A covert method of decryption exploiting the so-called birthday paradox.

The genetic father of a child (as opposed to an adoptive father or stepfather).

Third-person singular simple present indicative form of give birth

(plural only, US, military slang) The brown-framed prescription eyeglasses issued to new recruits in the U.S. military, and perceived as notoriously unattractive.

(probability theory) The mathematics problem that concerns the probability there exist two people in a random group who share a birthday.

(medicine) Any of several medical disorders that are present at birth.

the year, month, and day of someone's birth; date of birth

plural of birthdate