I will tell you the etymology of the word "underwear". Long, long ago, when everybody ran around with uncovered bottoms, a certain Jacques Trappe invented briefs to prevent em-bare-assment. He presented a prototype of the remarkable garment to the king, who looked at them, puzzled.
"Upon what part of my body does this thing fit?" said the king.
Jacques whispered into the king's ear, and the king shouted "Under WHERE?"
And we've called it underwear ever since.