Malignant meaning: Malignant Medspeak adjective Tending to

malignant Medspeak adjective Tending to harm, kill, maim; pernicious, life-threatening; resistant to treatment; severe (as in malignant hypertension); threatening to life; virulent. Oncology adjective Referring to invasion and destruction of nearby tissue and spread to regions; referring to a neoplasm that invades surrounding tissue—which generally is unencapsulated—and grows by invasion, with vascular and lymphatic metastases. Malignant definition : disposed to cause harm, suffering, or distress deliberately; feeling or showing ill will or hatred.. See examples of MALIGNANT used in a sentence. For something that's very harmful, especially a tumor that's cancerous, use the term malignant .