IPA: /məˈlɛəriəl/
KK: /məˈlɛrɪəl/
Relating to or caused by a disease transmitted by mosquitoes, known as malaria.
The patient was diagnosed with a malarial infection after returning from a tropical region.
Malarial → It is derived from "malaria" (from Italian *mal'aria*, meaning bad air), which refers to the disease caused by parasites transmitted through the bite of infected mosquitoes. The suffix "-al" (meaning pertaining to) indicates that it relates to malaria. Thus, "malarial" means pertaining to or caused by malaria.
Think of 'bad air' ('mal' and 'aria') that leads to illness, which helps you remember that 'malarial' refers to something related to the disease malaria.