/noog"ee/ , n. Slang.
a light blow or jab, usually to a person's head, back, or upper arm and accompanied by a twisting motion, with the extended knuckle of the curled-up second or third finger: done as a gesture of affection or painfully as a prank.
Also, nuggie, nugie .
[ 1975-80; appar. expressive alter. of KNUCKLE; see -Y 2 ]