Definition of "illuminant" [il•lu•mi•nant]

• Something that gives off light. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Rockefellers as soon as the sun goes down, no matter what form of illuminant they use."
• "I had a dream last night it was the illuminant who was stirring all this controversy over the health care bill ........"
• "What Don said is, I think, perfectly correct when talking about saturation, my point was just that Jim wasn't talking about saturation but about chroma, and not about emmited lights but about reflective surfaces under a given illuminant, so, in my view, Don was correct but beyond the point."