n.
Pronunciation: ' lü-m ə n
Function: noun
Inflected Form: plural lumens also lu · mi · na \ -m ə -n ə \
Etymology: New Latin lumin-, lumen, from Latin, light, air shaft, opening
Date: 1873
1 : the cavity of a tubular organ or part <the lumen of a blood vessel>
2 : the bore of a tube (as of a hollow needle or catheter)
3 : a unit of luminous flux equal to the light emitted in a unit solid angle by a uniform point source of one candle intensity
– lu · mi · nal also lu · men · al \ -m ə -n ə l \ adjective