1. a device or system that removes frost or ice from a surface, especially the windshield or windows of a vehicle
2. a kitchen appliance or setting used to thaw frozen food
Usage: less common than sense 1

Examples

• Turn on the defroster to clear the ice from the windshield.
• The car's rear defroster helps remove condensation from the back window.
• I used the microwave's defroster setting to thaw the chicken.
• On cold mornings, I always activate the defroster before driving.
• The defroster in my truck works quickly in winter weather.
• She switched on the front defroster as frost began to form on the glass.