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
large or relatively large in number or amount or extent or degree; "a considerable quantity"; "the economy was a considerable issue in the campaign"; "went to considerable trouble for us"; "spent a considerable amount of time on the problem"