We found 38 dictionaries that define the word positron:

General (21 matching dictionaries)

1. positron: Longman Dictionary of Contemporary English
2. positron: Merriam-Webster
3. positron: Oxford Learner's Dictionaries
4. positron: American Heritage Dictionary of the English Language
5. positron: Collins English Dictionary
6. positron: Vocabulary.com
7. Positron, positron: Wordnik
8. positron: Cambridge Advanced Learner's Dictionary
9. positron: Wiktionary
10. positron: Webster's New World College Dictionary, 4th Ed.
11. positron: The Wordsmyth English Dictionary-Thesaurus
12. positron: Infoplease Dictionary
13. positron: Dictionary.com
14. positron: Online Etymology Dictionary
15. Positron (video game), Positron: Wikipedia, the Free Encyclopedia
16. positron: Rhymezone
17. positron: FreeDictionary.org
18. positron: Mnemonic Dictionary
19. positron: TheFreeDictionary.com

Computing (1 matching dictionary)

20. positron: Encyclopedia

Medicine (4 matching dictionaries)

21. positron: Merriam-Webster Medical Dictionary
22. Dorland's Illustrated Medical Dictionary (No longer online)
23. online medical dictionary (No longer online)
24. positron: Medical dictionary

Miscellaneous (1 matching dictionary)

25. Encyclopedia of Graphic Symbols (No longer online)

Science (7 matching dictionaries)

26. Chemistry Dictionary (No longer online)
27. Positron: Eric Weisstein's World of Physics
28. Imagine the Universe! Dictionary (No longer online)
29. Positron: Extragalactic Astronomy
30. Positron: NRC Glossary of Nuclear Terms --
31. POSITRON: Zoom Astronomy Glossary
32. Accelerator Glossary (No longer online)

Slang (1 matching dictionary)

33. positron: Urban Dictionary

Sports (1 matching dictionary)

34. Positron: Bicycle Glossary

Tech (2 matching dictionaries)

35. High-Energy Astrophysics (No longer online)
36. Glossary of Meteorology (No longer online)

(Note: See positrons as well.)

Definitions from Wiktionary ( ) ▸ noun:  (physics) The antimatter equivalent of an electron, having the same mass but a positive charge. Similar: antielectron, positronium, positon, antiproton, protonium, antihydrogen, protron, spositron, proton, antiparticle, more... Phrases: Positron emission, positron decay, positron emission tomography, positron emission tomography scanner, positron emission tomography scan, more... Adjectives: electron, free, emitted, scattered, trapped, slow, energetic, single, high, incoming, dynamic Colors:     neon pink,     electric blue,     lime green,     bright yellow,     vivid orange, more... ▸ Word origin ▸ Words similar to positron ▸ Usage examples for positron ▸ Idioms related to positron ▸ Wikipedia articles (New!) ▸ Popular adjectives describing positron ▸ Words that often appear near positron ▸ Rhymes of positron ▸ Invented words related to positron