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
ready and able to resort to force or violence; "pugnacious spirits...lamented that there was so little prospect of an exhilarating disturbance"- Herman Melville; "they were rough and determined fighting men"