Lumen (Noun)
Meaning 1
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.
Classification
Nouns denoting quantities and units of measure.
Synonyms
Meaning 2
A cavity or passage in a tubular organ; "the lumen of the intestine".
Classification
Nouns denoting body parts.