We found 32 dictionaries that define the word sine qua non:

General (21 matching dictionaries)

1. sine qua non: Longman Dictionary of Contemporary English
2. sine qua non: Merriam-Webster
3. sine qua non: Oxford Learner's Dictionaries
4. sine qua non: American Heritage Dictionary of the English Language
5. sine qua non: Collins English Dictionary
6. sine qua non: Vocabulary.com
7. sine qua non: Wordnik
8. sine qua non: Cambridge Advanced Learner's Dictionary
9. sine qua non: Wiktionary
10. sine qua non: The Wordsmyth English Dictionary-Thesaurus
11. sine qua non: Infoplease Dictionary
12. sine qua non: Dictionary.com
13. sine qua non: Online Etymology Dictionary
14. Sine Qua Non (Battlestar Galactica), Sine Qua Non (wine), Sine qua non: Wikipedia, the Free Encyclopedia
15. sine qua non: Rhymezone
16. sine qua non: FreeDictionary.org
17. sine qua non: Mnemonic Dictionary
18. sine qua non: Foreign Words and Phrases
19. sine qua non: TheFreeDictionary.com

Art (2 matching dictionaries)

20. sine qua non: Dictionary of Philosophical Terms and Names
21. sine qua non: Global Glossary

Business (4 matching dictionaries)

22. sine qua non: Law.com Dictionary
23. Everybody's Legal Dictionary (No longer online)
24. sine qua non: Legal dictionary
25. BusinessDictionary.com (No longer online)

Miscellaneous (1 matching dictionary)

26. sine qua non: Wordcraft Dictionary

Religion (1 matching dictionary)

27. Irivng Hexham's Concise Dictionary of Religion (No longer online)

Science (2 matching dictionaries)

28. sine qua non: PlanetMath Encyclopedia
29. FOLDOP - Free On Line Dictionary Of Philosophy (No longer online)

Slang (1 matching dictionary)

30. sine qua non: Urban Dictionary

(Note: See sine_qua_nons as well.)

Definitions from Wiktionary (sine qua non) ▸ noun:  An essential or indispensable element, condition, or ingredient. Similar: essential condition, sinequanon, coessentiality, element, penumbra, necessary condition, coessentialness, necessitude, conditional, supplementarity, more... Opposite: inessential, nonessential, extraneous, peripheral Types: essential, indispensable, necessary, requisite, more... Phrases: conditio sine qua non, the opposite of sine qua non, more... Adjectives: requisite, self-existent, existential, consequential, nascent, essential, built-in, subsistent, suppletive, coessential, existent ▸ Word origin ▸ Words similar to sine qua non ▸ Usage examples for sine qua non ▸ Idioms related to sine qua non ▸ Wikipedia articles (New!) ▸ Words that often appear near sine qua non ▸ Rhymes of sine qua non ▸ Invented words related to sine qua non