Idioms and Phrases with below the belt, hit
below the belt, hit
Not behave according to the rules or decency, unfairly, as in Bringing up my mother's faults—that's really hitting below the belt. The term comes from boxing, where according to the Marquis of Queensberry Rules (1865) a fighter may punch his opponent only in the upper body or head. For a synonym, see low blow; also see under one's belt.