1. substances or products that make something brighter or whiter, especially optical brightening agents added to detergents and fabrics
2. cosmetic products used to make skin appear brighter or more radiant

Examples

• The laundry detergent contains optical brighteners to make white clothes appear whiter.
• Many fabric brighteners work by absorbing ultraviolet light and reflecting it as visible blue light.
• She applied face brighteners to give her complexion a healthy glow.
• The makeup artist used brighteners under the model’s eyes to reduce dark circles.
• Some brighteners in cleaning products can cause skin irritation in sensitive individuals.
• Natural brighteners like lemon juice have been used for centuries to whiten fabrics.