We found 35 dictionaries that define the word insidious:

General (26 matching dictionaries)

1. insidious: Merriam-Webster.com
2. insidious: Oxford Learner's Dictionaries
3. insidious: American Heritage Dictionary of the English Language
4. insidious: Collins English Dictionary
5. insidious: Vocabulary.com
6. Insidious, insidious: Wordnik
7. insidious: Cambridge Advanced Learner's Dictionary
8. insidious: Wiktionary
9. insidious: Webster's New World College Dictionary, 4th Ed.
10. insidious: The Wordsmyth English Dictionary-Thesaurus
11. insidious: Infoplease Dictionary
12. insidious: Dictionary.com
13. insidious: Online Etymology Dictionary
14. insidious: Cambridge Essential American English Dictionary
15. Insidious (Nightrage album), Insidious (film), Insidious (film series), Insidious: Wikipedia, the Free Encyclopedia
16. Insidious: Online Plain Text English Dictionary
17. insidious: Webster's Revised Unabridged, 1913 Edition
18. insidious: Rhymezone
19. Insidious: AllWords.com Multi-Lingual Dictionary
20. insidious: Webster's 1828 Dictionary
21. insidious: Free Dictionary
22. insidious: Mnemonic Dictionary
23. insidious: LookWAYup Translating Dictionary/Thesaurus
24. insidious: Dictionary/thesaurus

Business (1 matching dictionary)

25. insidious: Legal dictionary

Computing (1 matching dictionary)

26. insidious: Encyclopedia

Medicine (6 matching dictionaries)

27. Dorland's Illustrated Medical Dictionary (No longer online)
28. online medical dictionary (No longer online)
29. Insidious: MEDLINE plus Illustrated Medical Encyclopedia
30. insidious: Medical dictionary
31. University of Maryland Glossary of Medical Terms (No longer online)
32. WeMove Glossary of Terms (No longer online)

Slang (1 matching dictionary)

33. insidious: Urban Dictionary

(Note: See insidiously as well.)

Definitions from Wiktionary ( ) ▸ adjective:  Producing harm in a stealthy, often gradual, manner. ▸ adjective:  Intending to entrap; alluring but harmful. ▸ adjective:  (nonstandard) Treacherous. Similar: harmful, pernicious, dangerous, seductive, subtle, unsafe, insiduous, unsudden, gradual, sneak, more... Opposite: blatant, overt, flagrant Types: covert, more... Phrases: insidious disease, insidious scheme, insidious claim, insidious cunning, insidious bad feature, more... Colors:     dark red,     midnight blue,     blood red ▸ Word origin ▸ Words similar to insidious ▸ Usage examples for insidious ▸ Idioms related to insidious ▸ Wikipedia articles (New!) ▸ Popular nouns described by insidious ▸ Words that often appear near insidious ▸ Rhymes of insidious ▸ Invented words related to insidious