1. not benign; harmful, malicious, or threatening
Usage: formal; relatively rare

Examples

• The doctor was concerned about the unbenign nature of the tumor.
• His unbenign intentions became clear when he refused to help.
• The critic’s unbenign review destroyed the young author’s confidence.
• What seemed like a minor issue proved to be unbenign in its effects.
• The unbenign influence of the corrupt official spread throughout the department.
• Her smile appeared friendly, but her unbenign motives were soon revealed.