Definition
The phrase 'below the belt' refers to an action that is unfair, unethical, or unsportsmanlike, especially in a competition or argument. It implies a personal attack or a low blow that violates accepted standards of decency. It suggests going too far and resorting to tactics that are morally reprehensible. It's like hitting someone when they're down or exploiting a vulnerability. Think of it as fighting dirty in a metaphorical sense.