We found 48 dictionaries that define the word illusion:

General (31 matching dictionaries)

1. illusion: Merriam-Webster.com
2. illusion: Oxford Learner's Dictionaries
3. illusion: American Heritage Dictionary of the English Language
4. illusion: Collins English Dictionary
5. illusion: Vocabulary.com
6. Illusion, illusion: Wordnik
7. illusion: Cambridge Advanced Learner's Dictionary
8. illusion: Wiktionary
9. illusion: Webster's New World College Dictionary, 4th Ed.
10. illusion: The Wordsmyth English Dictionary-Thesaurus
11. illusion: Infoplease Dictionary
12. illusion: Dictionary.com
13. illusion: Online Etymology Dictionary
14. illusion: Cambridge Essential American English Dictionary
15. Illusion (Krassimir Avramov song), Illusion (Poor Moon EP), Illusion (Renaissance album), Illusion (Shahin Najafi album), Illusion (UK band), Illusion (band), Illusion (company), Illusion (disambiguation), Illusion (keelboat), Illusion (musical), Illusion (series), Illusion (video game series), Illusion, The Illusion (Animorphs), The Illusion (album), The Illusion (band), The Illusion (novel), The Illusion (play): Wikipedia, the Free Encyclopedia
16. Illusion: Online Plain Text English Dictionary
17. illusion: Webster's Revised Unabridged, 1913 Edition
18. illusion: Rhymezone
19. Illusion (f), illusion, illusion (f): AllWords.com Multi-Lingual Dictionary
20. illusion: Webster's 1828 Dictionary
21. illusion: Free Dictionary
22. illusion: Mnemonic Dictionary
23. illusion: LookWAYup Translating Dictionary/Thesaurus
24. illusion: Dictionary/thesaurus

Art (1 matching dictionary)

25. illusion: ArtLex Lexicon of Visual Art Terminology

Business (2 matching dictionaries)

26. Bouvier's Law Dictionary 1856 Edition (No longer online)
27. illusion: Legal dictionary

Computing (1 matching dictionary)

28. illusion: Encyclopedia

Medicine (8 matching dictionaries)

29. Dorland's Illustrated Medical Dictionary (No longer online)
30. Illusion: MedTerms.com Medical Dictionary
31. Illusion: MedFriendly Glossary
32. illusion: Sound Alike Words
33. online medical dictionary (No longer online)
34. Terms in the field of Psychiatry and Neurology (No longer online)
35. illusion: Medical dictionary
36. Illusion: Drug Medical Dictionary

Miscellaneous (2 matching dictionaries)

37. Sound-Alike Words (No longer online)
38. Illusion: Glossary of Terms in Parapsychology

Science (1 matching dictionary)

39. Illusion: Eric Weisstein's World of Mathematics

Slang (1 matching dictionary)

40. illusion: Urban Dictionary

Tech (1 matching dictionary)

41. Textile (No longer online)

(Note: See illusional as well.)

Definitions from Wiktionary ( ) ▸ noun:  (countable) Anything that seems to be something that it is not. ▸ noun:  (countable) A misapprehension; a belief in something that is in fact not true. ▸ noun:  (countable) A magician’s trick. ▸ noun:  (uncountable) The state of being deceived or misled. Similar: fantasy, phantasy, fancy, legerdemain, magic trick, magic, semblance, deception, trick, head game, more... Opposite: reality, truth, fact, certainty, authenticity Types: optical illusion, mirage, ponzo illusion, size illusion, visual illusion, more... Phrases: optical illusion, money illusion, moon illusion, Ponzo illusion, perceptual illusion, more... Adjectives: optical, mere, dramatic, dangerous, pure, visual, theatrical, romantic, grand, complete, perfect ▸ Word origin ▸ Words similar to illusion ▸ Usage examples for illusion ▸ Idioms related to illusion ▸ Wikipedia articles (New!) ▸ Popular adjectives describing illusion ▸ Words that often appear near illusion ▸ Rhymes of illusion ▸ Invented words related to illusion