We found 19 dictionaries that define the word piston ring:

General (16 matching dictionaries)

1. piston ring: Longman Dictionary of Contemporary English
2. piston ring: Merriam-Webster
3. piston ring: Oxford Learner's Dictionaries
4. piston ring: American Heritage Dictionary of the English Language
5. piston ring: Collins English Dictionary
6. piston ring: Vocabulary.com
7. piston ring: Wordnik
8. piston ring: Wiktionary
9. piston ring: The Wordsmyth English Dictionary-Thesaurus
10. piston ring: Infoplease Dictionary
11. Piston ring, piston ring: Dictionary.com
12. Piston ring: Wikipedia, the Free Encyclopedia
13. piston ring: Rhymezone
14. piston ring: FreeDictionary.org
15. piston ring: Mnemonic Dictionary
16. piston ring: TheFreeDictionary.com

Computing (1 matching dictionary)

17. piston ring: Encyclopedia

Sports (1 matching dictionary)

18. Internet Karting Glossary (No longer online)

Tech (1 matching dictionary)

19. AUTOMOTIVE TERMS (No longer online)

(Note: See piston_rings as well.)

Definitions from Wiktionary (piston ring) ▸ noun:  A ring or seal that fits around a piston, sealing between the piston and the bore in which it slides. Similar: piston rod, snap ring, trunk piston, piston, gudgeon pin, slave cylinder, penis ring, prison ring, olive, pistonphone, more... ▸ Words similar to piston ring ▸ Usage examples for piston ring ▸ Idioms related to piston ring ▸ Wikipedia articles (New!) ▸ Words that often appear near piston ring ▸ Rhymes of piston ring ▸ Invented words related to piston ring