1. in a way that causes extreme fear or terror
2. to an extreme or shocking degree
Usage: informal

Examples

• The monster in the movie was terrifyingly realistic.
• She drove terrifyingly fast down the winding mountain road.
• The storm approached terrifyingly quickly.
• His grades dropped terrifyingly low this semester.
• The building swayed terrifyingly during the earthquake.
• The cost of college has risen terrifyingly in recent years.