1. in an extremely large or impressive manner; enormously
2. to an extreme degree; extremely (often used to intensify an adjective or verb)
Usage: informal

Examples

• The new stadium is colossally larger than the old one.
• She made a colossally stupid mistake that cost the company millions.
• The project was colossally over budget.
• That performance was colossally impressive.
• He colossally underestimated the difficulty of the task.
• The two buildings are colossally different in design.
• The event was a colossally successful fundraiser.