Main Entry: ma·lig·nant

Pronunciation: \mə-ˈlig-nənt\

Function: adjective

1 : tending to produce death or deterioration <malignant malaria> ; especially : tending to infiltrate, metastasize, and terminate fatally <malignant tumors>—compare benign 1
2 : of unfavorable prognosis : not responding favorably to treatment <psychotic reactions with a malignant trend>