lumen(redirected from lumina)
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n. pl. lu·mens or lu·mi·na (-mə-nə)
1. Anatomy The inner open space or cavity of a tubular organ, as of a blood vessel or an intestine.
2. Biology The interior of a membrane-bound compartment or organelle in a cell.
3. Abbr. lm Physics The SI unit of luminous flux, equal to the amount of light per unit time passing through a solid angle of one steradian from a light source of one candela intensity radiating equally in all directions. See Table at measurement.
lu′men·al, lu′min·al adj.
n, pl -mens or -mina (-mɪnə)
1. (Units) 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
2. (Anatomy) anatomy a passage, duct, or cavity in a tubular organ
3. (Botany) a cavity within a plant cell enclosed by the cell walls
[C19: New Latin, from Latin: light, aperture]
ˈlumenal, ˈluminal adj
n., pl. -mens, -mi•na (-mə nə)
1. the unit of luminous flux, equal to the luminous flux emitted in a unit solid angle by a point source of one candle intensity. Abbr.: lm
2. the canal, duct, or cavity of a tubular organ.
[1870–75; < New Latin; Latin lūmen, s. lūmin- light, window]
1. Anatomy The central space in a tubular organ, such as a blood vessel or intestine.
2. Physics A unit used to measure the amount of light passing through a given area per second. One lumen is equal to the amount of light that passes through a given area (shaped like a cone) that is illuminated by a light with a brightness of one candela.
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|Noun||1.||lumen - 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|
luminous flux unit - a measure of luminous flux per unit area
|2.||lumen - a cavity or passage in a tubular organ; "the lumen of the intestine"|