1. very; extremely
Usage: informal
2. in a terrible manner; badly or severely

Examples

• I’m terribly sorry for being late.
• The weather has been terribly hot this week.
• She performed terribly on the exam.
• The team played terribly in the first half.
• I’m terribly excited about the trip.
• The accident victim was terribly injured.
• He felt terribly guilty about his mistake.