Lumen

[lu:min]

解釋/意思:

(noun.) a cavity or passage in a tubular organ; 'the lumen of the intestine'.

(noun.) 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.

整理:维维安--From WordNet