nipplebrain Share definition Flag A word made up to make fun of people...call who ever you want a nipplebrain, and they won't have a better comeback... 'Shut the hell up, you fucking nipplebrain...' nipplebrain by T-Ravis April 7, 2004 0 0 Get merch Get the nipplebrain mug. Buy Now — $32.95 See more merch