Found 2 items, similar to Lumen.
English → English (WordNet) Definition: lumen lumen n 1: 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 [syn: lm] 2: a cavity or passage in a tubular organ; “the lumen of the intestine” [also: lumina (pl)]
English → English (gcide) Definition: Lumen Lumen \Lu"men\, n.; pl. L. Lumina, E. Lumens. [L., light, an opening for light.] 1. (Photom.) (a) A unit of illumination, being the amount of illumination of a unit area of spherical surface, due to a light of unit intensity placed at the center of the sphere. (b) A unit of light flux, being the flux through one square meter of surface the illumination of which is uniform and of unit brightness. [Webster 1913 Suppl.] 2. (Biol.) An opening, space, or cavity, esp. a tubular cavity; a vacuole. [Webster 1913 Suppl.]