lumen

[ loo-muhn ]

/ ˈlu mən /

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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.

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Origin of lumen

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

Words nearby lumen

lumbricide, lumbricoid, lumbricosis, lumbricus, lumbus, lumen, lumen-hour, lum-hat, Lumholtz's kangaroo, Lumière, Luminaire

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use lumen in a sentence

That’s why it’s best to look at the lumens instead of the wattage.
The best floodlight: Light up the night and the driveway with these outdoor lighting fixtures|Irena Collaku|July 13, 2021|Popular-Science
Besides lumens, the biggest factor for finding the best floodlight is position.
The best floodlight: Light up the night and the driveway with these outdoor lighting fixtures|Irena Collaku|July 13, 2021|Popular-Science
The number of lumens needed for an outdoor floodlight is between 700 and 2,5000.
The best floodlight: Light up the night and the driveway with these outdoor lighting fixtures|Irena Collaku|July 13, 2021|Popular-Science
Be sure to pay attention to the lumens or wattage of a light fixture – no dimly lit spaces here.
Tips to properly prep your home to sell for the most|Justin Noble|June 24, 2021|Washington Blade

For huge spacesA junk-drawer flashlight’s brightness measures in the hundreds of lumens.
Treat yourself to a flashlight that’s not your phone|Rob Verger|December 15, 2020|Popular-Science
That reminds me, I'd better arrange a debate on immigration for the Lumen.
Ramsey Milholland|Booth Tarkington
"She made a splendid impression on the Lumen," Colburn went on.
Ramsey Milholland|Booth Tarkington
In the second main variety of gland the secretory portion is enlarged and the lumen variously increased in size.
Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 6|Various
At about the time when a lumen appears in the Oviduct the first traces of the Wolffian duct become visible.
The Works of Francis Maitland Balfour, Volume 1|Francis Maitland Balfour
While undergoing this change of position it also acquires a lumen, but ends blindly both in front and behind.
The Works of Francis Maitland Balfour, Volume 1|Francis Maitland Balfour

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 candelaSymbol: 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

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for lumen

lumen

[ lōō′mən ]

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

lu′men•al null adj.

Scientific definitions for lumen

lumen

[ lōō′mən ]

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.