The phrase “in the buff” is a playful way to say someone is naked, but it actually began with leather. In the 17th century, “buff” referred to a soft, tan leather made from buffalo or ox hide, which was similar in color to human skin. People began using “buff” to describe that bare-skin tone.

There is also a military twist. Soldiers once wore buff-colored tunics, and when out of full uniform, they were described as being “in the buff.” Over time, the phrase stuck and eventually took on its cheekier modern meaning.