(noun): The terminology used to describe the neck of one, typically a man, who has outrageous and absurd amounts of hair on the back of their neck. Where the hairline typically ends, his continues past his collar and into his shirt - possibly uniting with his back hair.
"I sit behind that kid in Geometry class, all I see is HAIR! He has such a Gorilla Neck!"
by GrossedOutGirl November 30, 2009