foot-lambert

or foot·lam·bert

[ foot-lam-bert ]

noun

, Optics.

1. a unit of luminance or photometric brightness, equal to the luminance of a surface emitting a luminous flux of one lumen per square foot, the luminance of a perfectly reflecting surface receiving an illumination of one foot-candle. : fL

foot-lambert

noun

1. a former unit of luminance equal to the luminance of a surface emitting or reflecting 1 lumen per square foot. A completely reflecting surface illuminated by 1 foot-candle has a luminance of 1 foot-lambert ft-L

Word History and Origins

Origin of foot-lambert¹

First recorded in 1920–25