infrared
n. uncountablen. a type of light that humans cannot see, but we can feel as heat. It is often used in technology like TV remotes or cameras that see in the dark.
n. electromagnetic radiation with wavelengths longer than those of visible light but shorter than microwaves. Often used in the context of thermal imaging or remote control technology.
The remote control uses infrared to change the channel.
Firefighters use infrared cameras to locate people through thick smoke by detecting their body heat.
By observing the universe in the infrared spectrum, astronomers can peer through dense clouds of cosmic dust that would otherwise obscure the formation of new stars.
From infra- + red.
Often used attributively (like an adjective) to modify other nouns, such as 'infrared light' or 'infrared sensor'.