from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The unit of brightness in the centimeter-gram-second system, equivalent to the brightness of a perfectly diffusing surface that emits or reflects one lumen per square centimeter.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. a cgs unit of illumination; the brightness of a surface that emits one lumen per square centimetre
After Johann Heinrich Lambert (1728-1777), German physicist and astronomer.(American Heritage® Dictionary of the English Language, Fourth Edition)