Pronunciation: lū′men, -min-ă, -menz
- The space in the interior of a hollow tubular structure (artery or intestine).
- The unit of luminous flux; the luminous flux emitted in a unit solid angle of 1 steradian by a uniform point source of light having a luminous intensity of 1 candela.
- The volume enclosed within the membranes of a mitochondrion or of the endoplasmic reticulum.
- The bore of a catheter or hollow needle.
[L. light, window]