Medical Dictionary


noun lu·men \ˈlü-mən\
plural lu·mi·na \-mə-nə\ or lumens

Medical 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 steradian by a uniform point source of one candle intensity


July 29, 2015
indomitable Hear it
incapable of being subdued or conquered
Take a 3-minute break and test your skills!
How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears