Below the belt and Low-down

Below the belt adjective - Disregarding the rules (from the notion of an illegal low blow in boxing).

Low-down and below the belt are semantically related in bit much topic. In some cases you can use "Low-down" instead an adjective phrase "Below the belt". informal substitute

Low-down adjective - Not following or in accordance with standards of honor and decency.

Below the belt and low-down are semantically related in not fair topic. Sometimes you can use "Below the belt" instead an adjective phrase "Low-down".