luminescence
- The emission of light by a substance that has not been heated, produced instead by chemical, biological, or electrical processes.
In a sentence
- The deep-sea diver was mesmerized by the blue-green luminescence emanating from the jellyfish drifting past the submersible.
- Scientists study bioluminescence as a form of luminescence that evolved independently dozens of times across marine species.
Usage note. Do not confuse 'luminescence' with 'incandescence'; luminescence specifically refers to light produced without significant heat, making it 'cold light.'
Where it comes from
English luminescence — “cold light emission” · entered English 19th c.
Formed in English from Latin 'lumen' (light, genitive 'luminis') combined with the suffix '-escence' (denoting a process or state). The root 'lumen' derives from Proto-Indo-European '*lewk-' meaning 'light' or 'to shine.' The word entered English in the late 19th century, around 1884, coined in scientific contexts to distinguish cold light emission from incandescence.