1. plural of lumen: units of measurement for the total amount of visible light emitted by a source
Usage: technical; lighting
2. plural of lumen: the hollow spaces inside tubular organs or structures in the body
Usage: medical; anatomy

Examples

• This LED bulb produces 800 lumens of bright white light.
• The new flashlight outputs 1000 lumens, making it perfect for camping.
• Energy-efficient bulbs can produce the same lumens while using less electricity.
• The doctor examined the lumens of the patient’s blood vessels.
• Blocked lumens in arteries can cause serious health problems.
• The microscope revealed the lumens of the intestinal tissue clearly.