1. in a serious or solemn manner
2. severely or critically (especially regarding illness or danger)

Examples

• The doctor spoke gravely about the patient’s condition.
• She nodded gravely when she heard the news.
• The situation has deteriorated gravely over the past week.
• He was gravely injured in the accident.
• The judge looked gravely at the defendant.
• The economy is gravely threatened by inflation.
• She gravely accepted the responsibility.