1. in a dark or gloomy manner; with a dark appearance or quality
2. in a threatening, ominous, or sinister manner
3. in an angry, hostile, or disapproving manner

Examples

• The sky hung blackly over the abandoned house.
• He stared blackly at his rival across the room.
• She spoke blackly of the company's unethical practices.
• The storm clouds gathered blackly on the horizon.
• He looked blackly displeased with the decision.
• The future seemed to stretch blackly before them.