n., the white chalk-like detritus of dry and flaky skin that often covers the surface area of the elbow; the word "ashy" is often used colloquially to describe a state of uniform bowdust coverage.
"I was on the roof last weekend cleaning out the gutters, when the ladder slipped out from under me. Instead of falling straight back, my slow-motion sideways descent through me right into a thicket of thorn-covered bushes. I wasn't hurt too bad, but I had what seemed like 100,000 scrapes on my arms and forearms. I went upstairs to wash off and check out the damage. I lifted my arms and looked and washed off the cuts. I must not have looked at my elbows in several months, because there was a snow-white layer of bowdust covering my elbow"