We found 30 dictionaries that define the word preposterous:

General (25 matching dictionaries)

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

Business (1 matching dictionary)

24. preposterous: Legal dictionary

Computing (1 matching dictionary)

25. preposterous: Encyclopedia

Medicine (1 matching dictionary)

26. online medical dictionary (No longer online)

Miscellaneous (1 matching dictionary)

27. preposterous: Wordcraft Dictionary

Slang (1 matching dictionary)

28. preposterous: Urban Dictionary

(Note: See preposterously as well.)

Definitions from Wiktionary ( ) ▸ adjective:  Absurd, or contrary to common sense. Similar: absurd, nonsensical, derisory, ludicrous, ridiculous, foolish, ass-backwards, sinistrous, contrary, imposterous, more... Opposite: sensible, rational, reasonable, logical Types: preposterously, preposterousness, preposterousnesses, more... Phrases: Captain Underpants and the Preposterous Plight of the Purple Potty People, most preposterous, more... Colors:     chartreuse,     fuchsia,     neon green,     electric blue,     hot pink, more... ▸ Word origin ▸ Words similar to preposterous ▸ Usage examples for preposterous ▸ Idioms related to preposterous ▸ Wikipedia articles (New!) ▸ Popular nouns described by preposterous ▸ Words that often appear near preposterous ▸ Rhymes of preposterous ▸ Invented words related to preposterous