Where does “extragalactic background light” come from?

extragalactic background light (English) comes from English extragalactic, from English galactic, from French galactique, from Latin galacticus, from Ancient Greek γαλακτικός, from Ancient Greek -ικός, from Ancient Greek -κός, from Proto-Indo-European -ḱos — -y, -ic.

extragalactic background light (English): All the accumulated radiation in the universe due to star formation processes, plus a contribution from active galactic nuclei (AGNs)

Definitions

  1. All the accumulated radiation in the universe due to star formation processes, plus a contribution from active galactic nuclei (AGNs)

Ancestry of “extragalactic background light”, step by step

extragalactic background light traces back through 3 separate lines of ancestry.

via English extragalactic

StepLanguageWordMeaning
1EnglishextragalacticOriginating outside of the Milky Way galaxy;...
2EnglishgalacticOf or pertaining to milk, or the secretion of...
3Frenchgalactiquegalactic; galactical
4Latingalacticusmilky
5Ancient Greekγαλακτικόςmilky; milky"
6Ancient Greek-ικόςof or pertaining to, in the manner of; -ic
7Ancient Greek-κόςforms adjectives with the sense of 'of or...
8Proto-Indo-European-ḱos-y, -ic

via English background

StepLanguageWordMeaning
1EnglishbackgroundLess important or less noticeable in a scene or...
2EnglishgroundThe surface of the Earth, as opposed to the sky...
3Middle Englishgroundground; Earth
4Old Englishgrundground; bottom, foundation; abyss, depths
5Proto-Germanicgrunduzground, foundation
6Proto-Indo-Europeangʰrem-to be angry; to sound, bellow, growl, roar, be...
7Proto-Indo-Europeangʰer-to rub; to stroke; to grind

via English Light

StepLanguageWordMeaning
1EnglishLightA place name
2Middle EnglishlightThe radiation which allows for vision by...
3Old Englishlēohtluminous, bright, light, clear, resplendent,...
4Proto-West Germanicleuhtlight, bright; light
5Proto-Germanicleuhtąlight
6Proto-Indo-Europeanlewktom
7Proto-Indo-Europeanlewk-bright; to shine; to see
Every word from Proto-Indo-European -ḱos
extragalactic background light — Etymology, Origin & Word History | Etymology Explorer