- Descriptive of invisible electromagnetic radiation that, when produced by a light source, is usually undesirable, except in certain industrial applications, such as drying and baking finished surfaces.
Information & Library Science
- noun a form of invisible light, below the visible red level on the light scale.
- adjective relating to infrared radiation
- adjective relating to a form of red light which is used in some night-viewing devices because it is invisible to the naked eye.