Lumen can mean:

• Lumen (unit), the SI unit of luminous flux
• Lumen (anatomy), the cavity or channel within a tubular structure
• Thylakoid lumen, the inner membrane space of the chloroplast
• 141 Lumen, an asteroid discovered by the French astronomer Paul Henry in 1875

See also

• Lux

Lumen | Lumen | Lumen | Lumen | Lumen | Lumen | Luumen | Lumen