We found 33 dictionaries that define the word useful:

General (25 matching dictionaries)

1. useful: Longman Dictionary of Contemporary English
2. useful: Merriam-Webster
3. useful: Oxford Learner's Dictionaries
4. useful: American Heritage Dictionary of the English Language
5. useful: Collins English Dictionary
6. useful: Vocabulary.com
7. Useful, useful: Wordnik
8. useful: Cambridge Advanced Learner's Dictionary
9. useful: Wiktionary
10. useful: Webster's New World College Dictionary, 4th Ed.
11. useful: The Wordsmyth English Dictionary-Thesaurus
12. useful: Infoplease Dictionary
13. The useful, useful: Dictionary.com
14. useful: Cambridge Essential American English Dictionary
15. Useful: Online Plain Text English Dictionary
16. useful: Webster's Revised Unabridged, 1913 Edition
17. useful: Rhymezone
18. Useful: AllWords.com Multi-Lingual Dictionary
19. useful: Webster's 1828 Dictionary
20. useful: FreeDictionary.org
21. useful: Mnemonic Dictionary
22. useful: TheFreeDictionary.com
23. useful: Wikimedia Commons US English Pronunciations

Business (3 matching dictionaries)

24. Bouvier's Law Dictionary 1856 Edition (No longer online)
25. useful: Legal dictionary
26. useful: Financial dictionary

Computing (1 matching dictionary)

27. useful: Encyclopedia

Miscellaneous (1 matching dictionary)

28. useful: Idioms

Science (1 matching dictionary)

29. useful: PlanetMath Encyclopedia

Slang (2 matching dictionaries)

30. useful, useful: Green’s Dictionary of Slang
31. useful: Urban Dictionary

(Note: See usefuling as well.)

Definitions from Wiktionary ( ) ▸ adjective:  Having a practical or beneficial use. Similar: important, valuable, utilizable, usable, utile, useable, reclaimable, serviceable, reusable, helpful, more... Opposite: useless, futile, ineffective, unproductive, worthless Types: useless, useless but cool, useless but fun, more... Phrases: useful life, useful arts, useful idiots, useful idiot, come in useful, more... Adjectives: more, very, other, small, how, several, some, ready, plutonium, various, directly Colors:     blue,     green,     gray,     white,     black, more... ▸ Words similar to useful ▸ Usage examples for useful ▸ Idioms related to useful ▸ Wikipedia articles (New!) ▸ Popular nouns described by useful ▸ Words that often appear near useful ▸ Rhymes of useful ▸ Invented words related to useful