Definitions
There are 2 meanings of the phrase
Below The Belt.
Below The Belt - as an adverb
Below The Belt - as an adjective satellite
Disregarding the rules (from the notion of an illegal low blow in boxing)
Example: "Her accusations were below the belt"
Example Sentences
"He hit his opponent below the belt during the boxing match."
"Using personal information against someone in an argument is hitting below the belt."
"I didn't appreciate her comments about my appearance, it felt below the belt."
"The comedian made a joke that was below the belt and offended many people."
"Bringing up someone's past mistakes during an argument is a below the belt tactics."