noun, plural ma·lig·nan·cies for 2, 3.
- the quality or condition of being malignant.
- malignant character, behavior, action, or the like: the malignancies of war.
- a malignant tumor.
noun plural -cies
- the state or quality of being malignant
- pathol a cancerous growth
n.c.1600, “malignant nature,” from malignant + -cy. Of growths, tumors, from 1680s. n.
- The state or quality of being malignant.
- A malignant tumor.