1. the action of making or becoming wider, larger, or more open
Usage: medical; formal
2. the condition of being dilated or expanded
Usage: medical; formal

Examples

• The doctor examined the dilatation of the patient’s pupils.
• Dilatation of blood vessels helps reduce blood pressure.
• The medication caused dilatation of the airways.
• Time dilatation occurs at very high speeds according to relativity theory.
• The dilatation of the cervix is monitored during labor.
• Heat causes dilatation of most metals.