plural lumens or lumina (-me-ne)
1.Anatomy. The inner open space or cavity of a tubular organ, as of a blood vessel or an intestine.
2.Abbr. lm Physics. The unit of luminous flux in the International System, equal to the amount of light given out through a solid angle by a source of one candela intensity radiating equally in all directions.
3.Botany. The cavity bounded by a plant cell wall.
[Latin, an opening, light.]
- lu´menal or lu´minal adjective
luminous flux (l¡´me-nes
The rate of flow of light per unit of time, especially the flux of visible light expressed in lumens.
Lumen, unit of luminous flux, the visible energy
emitted into a given solid angle by a light source per unit time. One lumen
equals the flux emitted in a unit solid angle, or steradian, by a point
source with a uniform intensity of one candela. The total luminous flux
of a light source divided by 4p equals the average candlepower of the source
measured in all directions.