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lumen

[loo-muh n] /ˈlu mən/
noun, plural lumens, lumina
[loo-muh-nuh] /ˈlu mə nə/ (Show IPA)
1.
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.
2.
Anatomy. the canal, duct, or cavity of a tubular organ.
3.
Botany. (of a cell) the cavity that the cell walls enclose.
Origin
1870-1875
1870-75; < Neo-Latin, special uses of Latin lūmen (stem lūmin-) light, window
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
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British Dictionary definitions for lumina

lumen

/ˈluːmɪn/
noun (pl) -mens, -mina (-mɪnə)
1.
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 lm
2.
(anatomy) a passage, duct, or cavity in a tubular organ
3.
a cavity within a plant cell enclosed by the cell walls
Derived Forms
lumenal, luminal, adjective
Word Origin
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
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Word Origin and History for lumina
lumen
unit of luminosity, 1898, coined 1894 in Fr. (A. Blondel) from L. lumen "light," related to lucere "to shine" (see light (n.)).
Online Etymology Dictionary, © 2010 Douglas Harper
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lumina in Medicine

lumen lu·men (lōō'mən)
n. pl. lumens or lu·mi·na (-mə-nə)

  1. The inner open space or cavity of a tubular organ, as of a blood vessel.

  2. The unit of luminous flux in the International System of Units, that is equal to the amount of light given out through a solid angle by a source of one candela intensity radiating equally in all directions.


lu'men·al or lu'min·al adj.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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lumina in Science
lumen
  (l'mən)   
Plural lumens or lumina
  1. The central space within a tube-shaped body part or organ, such as a blood vessel or the intestine.

  2. 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.


The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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