1. To condemn, to accuse, or to speak out against someone or something: Marcus stood on the street corner denouncing the city's injustices against poor people.

Kent's plan for increasing the company's profits was denounced by his supervisor as being risky and dangerous.

2. To report someone to the police or other authorities for illegal or immoral acts: Kim's cousin decided to go to another country after he was denounced by bank authorities as a swindler or con artist of bank accounts.