Home Dee Dee Word of the Day – Feb. 13 – Mutt Dee Dee Word of the Day – Feb. 13 – Mutt By Staff mB - February 13, 2012 1334 Noun: Mutt (MUT) Definition: 1. A stupid or insignificant person: fool. 2. A mongrel dog. Sample sentence: The best dog I ever had was no purebred, but a beautiful mutt.