Definition of "infrared" []

• Of or relating to the range of invisible radiation wavelengths from about 750 nanometers, just longer than red in the visible spectrum, to 1 millimeter, on the border of the microwave region. (adjective)
• Generating, using, or sensitive to infrared radiation. (adjective)
• Infrared light or the infrared part of the spectrum. (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.

• "Anyone who understands chemistry also knows that carbon dioxide is a gas that transmits visible light, but attempts to retain infrared radiation."
• "And here, made with the 31-inch telescope at UVa's Fan Mountain in the infrared, is M51:"
• "I bet he sees everything in infrared like the Predator, too."