1. in a serious, grave, or formal manner
2. in a way that shows deep respect or reverence, especially in religious contexts

Examples

• The judge solemnly pronounced the verdict.
• She solemnly promised to keep the secret.
• The congregation solemnly bowed their heads in prayer.
• He solemnly swore to tell the truth in court.
• The flag was solemnly raised at dawn.
• The priest solemnly blessed the newborn child.
• They solemnly observed a moment of silence.