Definition of Benign: Benign (adjective): Gentle and kind; not harmful in effect. In medical terms, it refers to a condition, tumor, or growth that is not cancerous. Synonyms: kind, gentle, harmless, mild Antonyms: malignant, harmful, severe, hostile Memory Tip: Think of “benign” as something that’s “benevolent” or “kind” in nature, not causing harm. Conversation and…