lumen

The lumen is a unit of measurement for the brightness of light. If a light bulb is blindingly bright, it produces a lot of lumens.

The lumen is a basic unit for measuring brightness, just as the gram is a basic unit for measuring mass. A typical light bulb in your home might produce about 1000 lumens. Lumen is related to the word luminous, which means “bright” or “radiant.”

Primary Meanings of lumen

1.
n
a cavity or passage in a tubular organ
2.
n
a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions
Full Definitions of lumen
1

n a cavity or passage in a tubular organ

“the lumen of the intestine”
Type of:
bodily cavity, cavity, cavum
(anatomy) a natural hollow or sinus within the body
2

n a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions

Synonyms:
lm
Type of:
luminous flux unit
a measure of luminous flux per unit area

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