We found 12 dictionaries that define the word positrons:

General (9 matching dictionaries)

1. positrons: Merriam-Webster
2. positrons: Collins English Dictionary
3. positrons: Vocabulary.com
4. positrons: Wordnik
5. positrons: Cambridge Advanced Learner's Dictionary
6. positrons: Wiktionary
7. positrons: Dictionary.com
8. Positrons: Wikipedia, the Free Encyclopedia
9. Positrons: TheFreeDictionary.com

Computing (1 matching dictionary)

10. Positrons: Encyclopedia

Medicine (2 matching dictionaries)

11. positrons: Merriam-Webster Medical Dictionary
12. Positrons: Medical dictionary

(Note: See positron as well.)

Definitions from Wiktionary (positron) ▸ noun:  (physics) The antimatter equivalent of an electron, having the same mass but a positive charge. ▸ Also see positron Opposite: electrons, negatrons, antiparticles ▸ Words similar to positrons ▸ Usage examples for positrons ▸ Idioms related to positrons ▸ Wikipedia articles (New!) ▸ Popular adjectives describing positrons ▸ Words that often appear near positrons ▸ Rhymes of positrons ▸ Invented words related to positrons