IPA: /kəˈlʌm.ni.əs/
KK: /kælˈʌm.ni.əs/
Describing something that is slanderous or harmful to someone's reputation.
The calumnious remarks made by the politician damaged his opponent's reputation.
Calumnious → It is formed from "calumnia" (meaning false accusation or slander) and the suffix "-ous" (meaning full of). The word "calumnious" means full of slander or characterized by false accusations.
Think of 'calumnia' which refers to slander, and remember that 'calumnious' describes someone or something that is full of slander.