1. not allowing light to pass through; impervious to light

Examples

• The photographer used a lightproof bag to load film into the camera.
• We need lightproof curtains for the darkroom.
• The storage container must be lightproof to preserve the chemicals.
• She sealed the box with lightproof tape to protect the sensitive materials.
• The lightproof cabinet keeps the photographic paper from being exposed.
• Make sure the door is lightproof before turning on the red light.