luminance
noun /ˈluːmɪnəns/
/ˈluːmɪnəns/
[uncountable] (physics- the amount of light given out in a particular direction from a particular area
亮度 词源late 19th cent. (as a general term meaning ‘light, brightness’): from Latin luminant- ‘illuminating’ (from the verb luminare) + -ance.