malignant

/məˈlɪɡnənt/adjective

Causing harm or intending evil; dangerous and destructive.

Example sentence

“The novel's antagonist takes a malignant delight in ruining others.”

In medicine it describes cancerous tumours; the opposite there is 'benign'.

Related words

tumorA lump of tissue that grows abnormally in the body; doctors distinguishing it may consider an abscess, metaplasia, or neoplasia.benignGentle and mild; causing no harm.cancerAn illness in which cells in part of the body begin to grow and multiply out of control.terminalThe building at an airport where travelers move between ground transport and their flights.diabetesDiabetes insipidus; any condition marked by the passing of unusually large or uncontrolled amounts of urine, now especially the form caused by the body failing to produce or respond to the hormone vasopressin.acuteVery strong, keen, or sharp in effect or perception.