Male back hair which may be manscaped into a decorative form or left au natural. The Fu Manchu backstache is when the tops of the shoulders are hairy, as are the sides of the back (covering part of the shoulderblades), but the center of the back is clean.
So we went to the beach, and Jim took off his shirt to reveal a backstache. It was terrifying in its raw manliness.
by Backstache hero November 12, 2008