We found 22 dictionaries that define the word radioactive decay:

General (11 matching dictionaries)

1. radioactive decay: American Heritage Dictionary of the English Language
2. radioactive decay: Collins English Dictionary
3. radioactive decay: Vocabulary.com
4. radioactive decay: Wiktionary
5. radioactive decay: Infoplease Dictionary
6. radioactive decay: Dictionary.com
7. Radioactive Decay, Radioactive decay: Wikipedia, the Free Encyclopedia
8. radioactive decay: Rhymezone
9. radioactive decay: FreeDictionary.org
10. radioactive decay: Mnemonic Dictionary
11. radioactive decay, decay, radioactive: TheFreeDictionary.com

Business (1 matching dictionary)

12. radioactive decay: Legal dictionary

Computing (1 matching dictionary)

13. radioactive decay, decay, radioactive: Encyclopedia

Medicine (2 matching dictionaries)

14. online medical dictionary (No longer online)
15. radioactive decay, decay, radioactive: Medical dictionary

Miscellaneous (1 matching dictionary)

16. Army Technology Glossary (No longer online)

Science (5 matching dictionaries)

17. Archaeology Wordsmith (No longer online)
18. Radioactive Decay: Eric Weisstein's World of Physics
19. Decay, radioactive, Radioactive decay: NRC Glossary of Nuclear Terms --
20. Anthropology dictionary (No longer online)
21. Atmospheric Chemistry and Air Quality (No longer online)

Tech (1 matching dictionary)

22. Glossary of Meteorology (No longer online)

(Note: See radioactive_decays as well.)

Definitions from Wiktionary (radioactive decay) ▸ noun:  (nuclear physics) Any of several processes by which unstable nuclei emit subatomic particles and/or ionizing radiation and disintegrate into one or more other nuclei. Similar: disintegration, decay, nuclear decay, nuclear disintegration, radioactivity, radiodecay, alpha decay, beta decay, neutron emission, alpha radiation, more... Opposite: radioactive growth, radioactive buildup Adjectives: radioactive, dirty, loft, radiogenic, cosmogenic, nuclear, purum, weapons-grade, autoradiographed, electrovalent, core ▸ Words similar to radioactive decay ▸ Usage examples for radioactive decay ▸ Idioms related to radioactive decay ▸ Wikipedia articles (New!) ▸ Words that often appear near radioactive decay ▸ Rhymes of radioactive decay ▸ Invented words related to radioactive decay