birthday suit

American  

noun

1. bare skin; nakedness.

   They were sunbathing in their birthday suits.

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birthday suit British  

noun

1. informal  a state of total nakedness, as at birth

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birthday suit Cultural  

1. To be “in one's birthday suit” is to be completely naked (as people are at birth).

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birthday suit Idioms  

1. 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.

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Etymology

Origin of birthday suit

First recorded in 1745–55

Example Sentences

The 61-year-old lifts weights, holds yoga poses, goes for a run in the park, meditates and does squats — all while in his birthday suit.

From Los Angeles Times

"Just hangin' out in my birthday suit," she captioned her photo.

From Fox News

"Just hangin' out in my birthday suit," the country music star captioned her photo.

From Fox News

For the shoot, the model stood against a bookshelf and a fireplace as she held a book in her birthday suit.

From Fox News

Bad idea: Post pics of your son in his birthday suit.

From Washington Post