/ məˈlɪgnənt; NAmE / adjective
1.
( of a tumour or disease ) that cannot be controlled and is likely to cause death :
malignant cells
—compare benign
OPP non-malignant
2.
( formal ) having or showing a strong desire to harm sb
SYN malevolent
••
WORD ORIGIN
mid 16th cent. (also in the sense likely to rebel against God or authority ): from late Latin malignant- contriving maliciously, from the verb malignare . The term was used in its early sense to describe Royalist sympathizers during the English Civil War.