We found 18 dictionaries that define the word don't know:

General (10 matching dictionaries)

1. don't-know: Oxford Learner's Dictionaries
2. don't know, don't know: Collins English Dictionary
3. don't-know: Vocabulary.com
4. don't know: Wiktionary
5. don't-know: Infoplease Dictionary
6. don't-know, don't know, dont-know, dont know: Dictionary.com
7. don't-know: Rhymezone
8. dont-know: FreeDictionary.org
9. don't-know: Mnemonic Dictionary
10. don't-know, don't know, dont-know: TheFreeDictionary.com

Business (5 matching dictionaries)

11. INVESTORWORDS (No longer online)
12. Don't know (DK, DKed): bizterms.net
13. Don't know: Bloomberg Financial Glossary
14. Comprehensive Financial (No longer online)
15. Don't Know: Financial dictionary

Computing (1 matching dictionary)

16. Don't know: Encyclopedia

Medicine (1 matching dictionary)

17. Don't know: Medical dictionary

Slang (1 matching dictionary)

18. don't know: Urban Dictionary

Definitions from Wiktionary (don't know) ▸ noun:  Someone who does not give a definite opinion in a questionnaire. ▸ noun:  Something about which one is uncertain. Phrases: dont know is born, dont know where to turn, dont know which way to turn, i dont know, dont know from adam, more... ▸ Words similar to don't know ▸ Usage examples for don't know ▸ Idioms related to don't know ▸ Wikipedia articles (New!) ▸ Words that often appear near don't know ▸ Rhymes of don't know ▸ Invented words related to don't know