Dictionary
lu•men
Pronunciation: (lOO'mun), [key]—
n.,
—pl. -mens, -mi•naPronunciation: (-mu-nu). [key]
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.
Abbr.: lm
2. Anat.the canal, duct, or cavity of a tubular organ.
3. Bot.(of a cell) the cavity that the cell walls enclose.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.