the infrared region of the electromagnetic spectrum; electromagnetic wave frequencies below the visible range; they could sense radiation in the infrared

[ Syn: infrared frequency ]

electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves

[ Syn: infrared light , infrared radiation , infrared emission ]

having or employing wavelengths longer than light but shorter than radio waves; lying outside the visible spectrum at its red end; infrared radiation; infrared photography'