We found 30 dictionaries that define the word tuning fork:

General (22 matching dictionaries)

1. tuning fork: Longman Dictionary of Contemporary English
2. tuning fork: Merriam-Webster
3. tuning fork: Oxford Learner's Dictionaries
4. tuning fork: American Heritage Dictionary of the English Language
5. tuning fork: Collins English Dictionary
6. tuning fork: Vocabulary.com
7. tuning-fork, tuning fork: Wordnik
8. tuning fork: Cambridge Advanced Learner's Dictionary
9. Tuning fork: InfoVisual Visual Dictionary
10. tuning fork: Wiktionary
11. tuning fork: The Wordsmyth English Dictionary-Thesaurus
12. tuning fork: Infoplease Dictionary
13. tuning fork: Dictionary.com
14. tuning fork: Online Etymology Dictionary
15. Tuning fork: Wikipedia, the Free Encyclopedia
16. tuning fork: Rhymezone
17. tuning-fork: Webster's 1828 Dictionary
18. tuning fork: FreeDictionary.org
19. tuning fork: Mnemonic Dictionary
20. tuning fork: TheFreeDictionary.com

Art (1 matching dictionary)

21. Virginia Tech Multimedia Music Dictionary (No longer online)

Business (1 matching dictionary)

22. tuning fork: Legal dictionary

Computing (1 matching dictionary)

23. Tuning-fork, tuning fork: Encyclopedia

Medicine (3 matching dictionaries)

24. tuning fork: Merriam-Webster Medical Dictionary
25. online medical dictionary (No longer online)
26. Tuning-fork, tuning fork: Medical dictionary

Science (1 matching dictionary)

27. Tuning Fork: Eric Weisstein's World of Physics

Slang (1 matching dictionary)

28. tuning fork: The Folk File

(Note: See tuning_forks as well.)

Definitions from Wiktionary (tuning fork) ▸ noun:  (music) A fork-shaped object which emits a tone of a specific frequency when struck, producing a reference note for tuning instruments. Similar: fork, pitchfork, tuning key, tuner, tuning peg, fourchette, shakefork, tuning head, pickfork, tone hole, more... Phrases: tuning fork auscultation, tuning fork principle, more... ▸ Word origin ▸ Words similar to tuning fork ▸ Usage examples for tuning fork ▸ Idioms related to tuning fork ▸ Wikipedia articles (New!) ▸ Words that often appear near tuning fork ▸ Rhymes of tuning fork ▸ Invented words related to tuning fork