When a nipple, usually during puberty, becomes hard like a nut under the skin; a common misconception is mistaking hard nipples due to cold weather or arousal for the nipple nut, however there's a fine line between them.
by The Dung Beetle May 5, 2009
A term used by older men who were seemingly in the military at one point in their lives and now employ the term in degrading high school athletes. Being a combonation of the simple terms nipple and nuts, it's effectiveness is increased tenfold.
If you don't finish this lap in under ten seconds nipple nuts, i will run your weak body into the ground!
by GK18 March 26, 2007