Below the belt意思

"Below the belt" is an English idiom that originates from the sport of boxing. In boxing, it refers to punches that are aimed below the waist, which is illegal and considered unsportsmanlike. The term has been metaphorically extended to describe any action or remark that is unfair, underhanded, or deliberately targeting a vulnerable or sensitive area in order to gain an advantage.

For example:

• "His personal attack on his opponent was considered below the belt."
• "The company's decision to suddenly change the terms of the contract was seen as below the belt by its partners."

In both cases, the implication is that the action or comment was inappropriate or unethical because it targeted an area that is considered off-limits or unfair in the context of the situation.