1. to remove fog or condensation from (a surface, especially a window or mirror)

Examples

• I used the defroster to defog the windshield before driving.
• She wiped the mirror with a cloth to defog it after her shower.
• The car's heating system helps defog windows on cold mornings.
• You can defog your glasses by breathing on them gently.
• The bathroom fan helps defog the mirror during humid weather.