Dictionary

lumen

noun lu·men \ˈlü-mən\

plural lumens also lu·mi·na \-mə-nə\

Definition of LUMEN

: the cavity of a tubular organ or part <the lumen of a blood vessel>

: the bore of a tube (as of a hollow needle or catheter)

: 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 \-mə-n^əl\ adjective

See lumen defined for kids

New Latin lumin-, lumen, from Latin, light, air shaft, opening

First Known Use: 1873

Medical Dictionary

noun lu·men \ˈlü-mən\

plural lu·mi·na \-mə-nə\ or lumens

: the cavity of a tubular organ or part <the lumen of a blood vessel>

: the bore of a tube (as of a hollow needle or catheter)

: a unit of luminous flux equal to the light emitted in a steradian by a uniform point source of one candle intensity

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