gag rule

noun

1. : a law, order, or ruling that prohibits free debate or expression of ideas, information, or opinions a long-standing Florida gag rule barring people from discussing complaints they made against police officers —National Law Journal specifically : a rule limiting or prohibiting debate on an issue in a legislative assembly (as the U.S. House of Representatives) : a rule limiting or prohibiting debate on an issue in a legislative assembly (as the U.S. House of Representatives)