lumen
/ˈlumən/
UK: /ˈluːmən/
lumen
English
Noun Top 36,652
Ad
Definition
In the International System of Units, the derived unit of luminous flux; the light that is emitted in a solid angle of one steradian from a source of one candela. Symbol: lm.
Etymology
Borrowed from Latin lūmen (“light, an opening”). Use as a unit was first adopted by French physicist André Blondel in 1894.
Ad