malarious UK /məˈlɛəɹi.əs/US /məˈlɛɹi.əs/ adjective2 •With malaria; where people may catch malaria.Dr. Abrams, the Columbia expert, said in an interview that the Uganda findings had additional implications for treating H.I.V.-infected children in malarious areas. — 2007 •Causing or relating to malaria. formsmore malarious · most malarious