We found 27 dictionaries that define the word background radiation:

General (13 matching dictionaries)

1. background radiation: Merriam-Webster
2. background radiation: Oxford Learner's Dictionaries
3. background radiation: Collins English Dictionary
4. background radiation: Vocabulary.com
5. background radiation: Cambridge Advanced Learner's Dictionary
6. background radiation: Wiktionary
7. background radiation: Dictionary.com
8. Background radiation: Wikipedia, the Free Encyclopedia
9. background radiation: Rhymezone
10. background radiation: FreeDictionary.org
11. background radiation: Mnemonic Dictionary
12. background radiation: TheFreeDictionary.com
13. background radiation: Merriam-Webster

Business (1 matching dictionary)

14. BusinessDictionary.com (No longer online)

Computing (1 matching dictionary)

15. background radiation: Encyclopedia

Medicine (5 matching dictionaries)

16. Background radiation, Radiation, background: MedTerms.com Medical Dictionary
17. Medical Dictionary (No longer online)
18. online medical dictionary (No longer online)
19. background radiation: Medical dictionary
20. Background radiation, Radiation, background: Drug Medical Dictionary

Science (5 matching dictionaries)

21. Chemistry Dictionary (No longer online)
22. Environmental Terminology Discovery Service (No longer online)
23. Background Radiation: Extragalactic Astronomy
24. Background radiation: NRC Glossary of Nuclear Terms --
25. BACKGROUND RADIATION: Zoom Astronomy Glossary

Tech (2 matching dictionaries)

26. AUTOMOTIVE TERMS (No longer online)
27. Nuclear Terms (No longer online)

(Note: See background_radiations as well.)

Definitions from Wiktionary (background radiation) ▸ noun:  ionizing radiation that is naturally present in the environment. Similar: background, cosmic background radiation, radioactivity, ultraviolet radiation, radiation, radiation damage, cosmic radiation, ionizing radiation, beta radiation, radiant energy, more... Opposite: direct radiation, primary radiation Phrases: cosmic background radiation, cosmic microwave background radiation, Discovery of cosmic microwave background radiation, more... ▸ Words similar to background radiation ▸ Usage examples for background radiation ▸ Idioms related to background radiation ▸ Wikipedia articles (New!) ▸ Words that often appear near background radiation ▸ Rhymes of background radiation ▸ Invented words related to background radiation