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
a passage, duct, or cavity in a tubular organ
3.
a cavity within a plant cell enclosed by the cell walls
Derived forms
lumenal (ˈlumenal) or luminal (ˈluminal)
adjective
Word origin
C19: New Latin, from Latin: light, aperture
lumen in American English
(ˈlumən)
nounWord forms: pluralˈlumens or ˈlumina (ˈlumɪnə)
1.
the basic unit used to measure the flow of light in the SI system, equal to the amount of light emitted through a solid angleof one steradian by a light source with the intensity of one candela (0.0015 watt)