a cavity or passage in a tubular organ; "the lumen of the intestine"
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
be left; of persons, questions, problems, results, evidence, etc.; "There remains the question of who pulled the trigger"; "Carter remains the only President in recent history under whose Presidency the U.S. did not fight a war"