A nipple knife is when a females nipple gets really hard and could be used to cut open a potato or any other hard object a knife can handle.
Last night my girl friend had her nipple knife out cutting the potatoes and slinging them into the hot boiling water to turn them into mashed potatoes.
by Hairythehippo November 4, 2014
Get the nipple knifemug. by Zonguestu August 29, 2017
Get the Knife nipplesmug.