lumen

Definitions

1. In the International System of Units, the derived unit of luminous flux; the light that is emitted in a solid angle of one steradian from a source of one candela. Symbol: lm.
2. light
3. The cavity or channel within a tube or tubular organ.
4. The cavity bounded by a plant cell wall.
5. brightness, intelligence
6. The bore of a tube such as a hollow needle or catheter.
7. focus, point of view, understanding
8. electric power

Equivalents

CEFR level