1. to become wider or larger; to make something wider or larger
2. to speak or write about something at length
Usage: formal

Examples

• The pupil dilates in dim light.
• The doctor dilates the patient’s eyes for the exam.
• Heat causes metal to dilate.
• Her blood vessels dilate when she exercises.
• The professor dilates on the importance of the discovery.
• The balloon dilates as we fill it with air.