infra-red

noun

1. the part of the invisible spectrum that is contiguous to the red end of the visible spectrum and that comprises electromagnetic radiation of wavelengths from 800 nm to 1 mm.

adjective

2. noting or pertaining to the infrared or its component rays: infrared radiation.

noun

1. the part of the electromagnetic spectrum with a longer wavelength than light but a shorter wavelength than radio waves; radiation with wavelength between 0.8 micrometres and 1 millimetre

adjective

2. of, relating to, using, or consisting of radiation lying within the infraredinfrared radiation

adj.

1. 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.
2. Generating, using, or sensitive to infrared radiation.

n.

1. Infrared light or the infrared part of the spectrum.

1. Relating to the invisible part of the electromagnetic spectrum with wavelengths longer than those of visible red light but shorter than those of microwaves. See more at electromagnetic spectrum.