"your bum floss is showing, pull up your pants."
by S_t_G October 14, 2004
A G-string. A piece of underwear that has a thin strip of fabric that hides in the crack between the buttock cheeks, rather than covering that crack like normal underwear. Named for the similarity with dental floss, that cleans the cracks between teeth.
"Look, She's wearing bumfloss. No wonder she's walking oddly"
by ClayPipe February 15, 2006