Liberal Dictionary English Dictionary
noun
- bare skin; nakedness: They were sunbathing in their birthday suits.
noun
- informal, jocular a state of total nakedness, as at birth
first attested 1730s, but probably much older. The notion is the suit of clothes one was born in, i.e., no clothes at all. Cf. Middle English mother naked “naked as the day one was born;” Middle Dutch moeder naect, German mutternackt.
To be “in one’s birthday suit” is to be completely naked (as people are at birth).
Nakedness, as in The doorbell rang, and here I was in my birthday suit. In 18th-century Britain this term originally referred to the clothes one wore on the king’s birthday. Later it was jocularly transferred to bare skin, alluding to the condition of a newborn baby.