1. in a way that shows no mercy or compassion; cruelly
2. to an extreme or excessive degree
Usage: informal

Examples

• The dictator ruled unmercifully over his people.
• She was teased unmercifully by her classmates.
• The sun beat down unmercifully on the desert travelers.
• He criticized her work unmercifully during the meeting.
• The storm raged unmercifully throughout the night.
• The coach pushed the team unmercifully during practice.
• The heat was unmercifully intense that summer.