We found 17 dictionaries that define the word beta rays:

General (9 matching dictionaries)

1. beta rays: Merriam-Webster
2. beta rays: Collins English Dictionary
3. beta rays: Vocabulary.com
4. beta rays: Wordnik
5. Beta rays: Dictionary.com
6. Beta rays: Wikipedia, the Free Encyclopedia
7. beta rays: Stammtisch Beau Fleuve Acronyms
8. beta rays: FreeDictionary.org
9. Beta rays, beta-rays: TheFreeDictionary.com

Computing (1 matching dictionary)

10. Beta rays, beta-rays: Encyclopedia

Medicine (5 matching dictionaries)

11. beta rays: Merriam-Webster Medical Dictionary
12. Dorland's Illustrated Medical Dictionary (No longer online)
13. Medical Dictionary (No longer online)
14. Medical Device Glossary of Terms (No longer online)
15. beta-rays, beta rays: Medical dictionary

Tech (2 matching dictionaries)

16. AUTOMOTIVE TERMS (No longer online)
17. Beta rays: Gems and Precious Stones

(Note: See beta_ray as well.)

Definitions from Wiktionary (beta ray) ▸ noun:  A stream of beta particles (fast-moving electrons propagating through a gas or vacuum), such as emitted by a radioactive substance. ▸ Also see beta_ray Types: positrons, electrons, more... ▸ Words similar to beta rays ▸ Usage examples for beta rays ▸ Idioms related to beta rays ▸ Wikipedia articles (New!) ▸ Words that often appear near beta rays ▸ Rhymes of beta rays ▸ Invented words related to beta rays