infrared /ˌɪnfɹəˈɹɛd/noun 3adjective 2forms 1 noun3 •The electromagnetic radiation of a wavelength longer than visible light, but shorter than microwave radiation, having a wavelength between 700 nm and 1 mm.Collisions of these 'transparent' molecules with the molecules that do have absorption bands in the infrared can have a considerable influence on the intensities of the observed absorption bands. — 1962 •A specific wavelength in this range.Sonne has shown that by means of the luminous rays the temperature in the tissue may be raised to a higher degree than by the use of the infrareds. — 1924 •A device that emits infrared radiation.In his room, he could install his infrareds without being discovered. — 2000 adjective2 •Having a wavelength in the infrared spectrum. •(figurative) Relating to very low energies or very large distances or time spans.Unless otherwise stated, we will be working in Euclidean space compactified to a sphere in order to avoid infrared problems. — 1986 formsinfrareds
