A descriptor for a beautiful woman or man, meaning the act of biting the middle knuckle of two fingers of a closed fist at the sight of beauty. Biting one finger would be a "single knuckle", biting two is a "double knuckle".
Did you see the new cashier lady at Safeway this week? Man, she's a total double knuckle.
by doogerotomy November 21, 2012