Naked, nude, bare … there are lots of ways in English to express the state of wearing no clothes, but in my opinion, the most humorous is the phrase birthday suit.
It’s easy to understand how this phrase came about. When you were born (i.e. your birth day), what clothes were you wearing? That’s why we describe nudity as wearing your birthday suit. According to the Oxford English Dictionary, this phrase has been in the language since the 18th century.
Native English speakers have a variety of ways to express nudity. “I’m in the buff,” is one example. “He’s in the altogether,” is another. But neither of these are quite as amusing as the phrase birthday suit. So next time someone knocks on your door when you’ve just got out of the shower, you can shout out, “Wait a minute! I’m in my birthday suit!”