1. in a way that causes great pain, suffering, or distress
2. in a way that is very wrong or offensive

Examples

• The soldier was grievously wounded in battle.
• She was grievously mistaken about his intentions.
• The company grievously underestimated the project costs.
• He felt grievously betrayed by his closest friend.
• The patient was grievously ill and required immediate surgery.
• The defendant had grievously violated the terms of his parole.