We found 46 dictionaries that define the word insomnia:

General (26 matching dictionaries)

1. insomnia: Merriam-Webster
2. insomnia: Oxford Learner's Dictionaries
3. insomnia: American Heritage Dictionary of the English Language
4. insomnia: Collins English Dictionary
5. insomnia: Vocabulary.com
6. Insomnia, insomnia: Wordnik
7. insomnia: Cambridge Advanced Learner's Dictionary
8. insomnia: Wiktionary
9. insomnia: Webster's New World College Dictionary, 4th Ed.
10. insomnia: The Wordsmyth English Dictionary-Thesaurus
11. insomnia: Infoplease Dictionary
12. insomnia: Dictionary.com
13. insomnia: Online Etymology Dictionary
14. insomnia: Cambridge Essential American English Dictionary
15. Insomnia (Craig David song), Insomnia (Daya song), Insomnia (Erick Sermon album), Insomnia (Faithless song), Insomnia (Hed PE album), Insomnia (The Hiatus EP), Insomnia (album), Insomnia (band), Insomnia (composition), Insomnia (disambiguation), Insomnia (film), Insomnia (novel), Insomnia (single), Insomnia (song), Insomnia (soundtrack), Insomnia: Wikipedia, the Free Encyclopedia
16. Insomnia: Online Plain Text English Dictionary
17. insomnia: Webster's Revised Unabridged, 1913 Edition
18. insomnia: Rhymezone
19. insomnia: AllWords.com Multi-Lingual Dictionary
20. insomnia: FreeDictionary.org
21. insomnia: Mnemonic Dictionary
22. insomnia: TheFreeDictionary.com
23. insomnia: Wikimedia Commons US English Pronunciations
24. insomnia: Longman Dictionary of Contemporary English

Business (1 matching dictionary)

25. insomnia: Financial dictionary

Computing (1 matching dictionary)

26. insomnia: Encyclopedia

Medicine (18 matching dictionaries)

27. insomnia: Merriam-Webster Medical Dictionary
28. Dorland's Illustrated Medical Dictionary (No longer online)
29. Insomnia: MedTerms.com Medical Dictionary
30. Breast Cancer Talking Dictionary (No longer online)
31. insomnia: Chronic Fatigue Syndrome Glossary
32. Insomnia: Merck Manuals
33. insomnia: Chronic Fatigue Syndrome
34. online medical dictionary (No longer online)
35. insomnia: Dictionary of Cancer Terms
36. Terms in the field of Psychiatry and Neurology (No longer online)
37. Glossary of HIV/AIDS Related Terms (No longer online)
38. Sleep Terms (No longer online)
39. insomnia: Medical dictionary
40. Rudy's List of Archaic Medical Terms (No longer online)
41. University of Maryland Glossary of Medical Terms (No longer online)
42. WeMove Glossary of Terms (No longer online)
43. Insomnia: Drug Medical Dictionary
44. Hyperdictionary (No longer online)

(Note: See insomniac as well.)

Definitions from Wiktionary ( ) ▸ noun:  (medicine) A sleeping disorder that is known for its symptoms of unrest and the inability to sleep. Similar: parasomnia, idiopathic hypersomnia, dyssomnia, agrypnia, sleep disorder, somnopathy, hypersomnia, sopor, somnipathy, hypersomnolence, more... Opposite: hypersomnia, hypnopompic Types: transient insomnia, middle insomnia, late insomnia, more... Phrases: chronic insomnia, primary insomnia, rebound insomnia, transient insomnia, terminal insomnia, more... Adjectives: chronic, primary, fatal, familial, severe, persistent, onset, initial, transient, psychophysiological, nervous Colors:     midnight blue,     charcoal,     slate gray,     deep purple,     indigo, more... ▸ Word origin ▸ Words similar to insomnia ▸ Usage examples for insomnia ▸ Idioms related to insomnia ▸ Wikipedia articles (New!) ▸ Popular adjectives describing insomnia ▸ Words that often appear near insomnia ▸ Rhymes of insomnia ▸ Invented words related to insomnia