lumen

[ loo-muh n ]
/ ˈlu mən /

noun, plural lu·mens, lu·mi·na [loo-muh-nuh] /ˈlu mə nə/.

Optics. the unit of luminous flux, equal to the luminous flux emitted in a unit solid angle by a point source of one candle intensity. Abbreviation: lm
Anatomy. the canal, duct, or cavity of a tubular organ.
Botany. (of a cell) the cavity that the cell walls enclose.

Origin of lumen

1870–75; < New Latin, special uses of Latin lūmen (stem lūmin-) light, window

Example sentences from the Web for lumen

British Dictionary definitions for lumen

lumen
/ (ˈluːmɪn) /

noun plural -mens or -mina (-mɪnə)

the derived SI unit of luminous flux; the flux emitted in a solid angle of 1 steradian by a point source having a uniform intensity of 1 candela Symbol: lm
anatomy a passage, duct, or cavity in a tubular organ
a cavity within a plant cell enclosed by the cell walls

Derived forms of lumen

lumenal or luminal, adjective

Word Origin for lumen

C19: New Latin, from Latin: light, aperture

Medical definitions for lumen

lumen
[ lōōmən ]

n. pl. lumens

The inner open space or cavity of a tubular organ, as of a blood vessel.
The unit of luminous flux in the International System of Units, equal to the amount of light given out through a solid angle by a source of one candela intensity radiating equally in all directions.

Other words from lumen

lumen•al null adj.

Scientific definitions for lumen

lumen
[ lōōmən ]

Plural lumens lumina

The central space within a tube-shaped body part or organ, such as a blood vessel or the intestine.
The SI derived unit used to measure the amount of light passing through a given area per second. One lumen is equal to the luminous flux passing per unit solid angle from a light source with a strength of one candela.