From Longman Dictionary of Contemporary Englishbelow the beltbelow the beltinformalUNFAIR unfair or cruel That was a bit below the belt, Paul. The comments hit below the belt (=they were unfair or cruel). → belt
Examples from the Corpus
below the belt• That was definitely a blow below the belt!• Whichever camp you are in, the same celestial advice will apply - hit below the belt.• Hits us below the belt as often as not. 