An Etymological Dictionary of Astronomy and Astrophysics

A centimeter-gram-second (cgs) unit of luminance (or brightness) equal to 1/π candle per square centimeter. Physically, the lambert is the luminance of a perfectly diffusing white surface receiving an illuminance of 1 lumen per square centimeter.

See also: Johann Heinrich Lambert (1728-1777), German scientist and mathematician; → law.