Top Dictionaries for Quick Lookup

AskOxford.com – The online version of the famous Oxford dictionary.

Dictionary.com – Dictionary.com is one of the most popular dictionaries on the web.
FreeDictionary.com – the Free dictionary.

Dictionaries

• American-Heritage Collegiate Dictionary
• Century Unabridged Dictionary (1889)
• Cambridge Dictionaries Online
• Historical Dictionary of American Slang
• Merriam-Webster Collegiate Dictionary
• New World College Dictionary
• Oxford English Dictionary (Subscription or Purchase Only)
• Wordnik English Dictionary
• Chambers (British) English Dictionary
• Dictionarium Britannicum
• Dictionary.com
• Encarta
• Get-Definition Dictionary
• Illustrated Semantically Organized Glossary
• Learning English Online
• Modern English-Indo-European Dictionary
• Newbury House Online Dictionary
• The Macquarie Dictionary (Australian—requires subscription)
• Wordnet English Dictionary and Thesaurus
• Wordsmyth

Specialty Dictionaries

• The Phrase Finder
• English Specialty Dictionaries (125 categories)
• Baby-Talk Dictionary
• Bartlett’s Dictionary of Americanisms
• Dictionary of Idioms
• Dictionary of Newfoundland English Online
• Dictionary of the Vulgar Tongue (1811)
• GoEnglish.com Idiom Dictionary
• Grandiloquent Dictionary
• Middle English Dictionary
• Piggot’s Political Dictionary (1795)
• Rhyming Dictionary and Thesaurus
• Scots English Dictionary

Grammars

• Directory of English Grammar
• A Brief Grammatical Sketch of English
• Advanced English Lessons
• Beginning English for Somali Speakers
• English Club English Grammar
• English Online from New Zealand Ministry of Education
• Eva Easton’s Basic English Grammar
• Online English Grammar
• Phonetics Flash Animation Project
• The Internet Grammar of English

General Dictionaries, Sorted by Number of Words in Database

1. Wikipedia, the Free Encyclopedia: [5278306 words]
2. Dictionary.com: [775929 words]
3. Dict.cc Englisch/Deutsch Wörterbuch: [750745 words]
4. Dict.cc Englisch/Deutsch Wörterbuch: [590803 words]
5. Wiktionary: [580200 words]
6. bab.la: [512709 words]
7. Wordnik: [472624 words]
8. Dictionary/thesaurus: [444483 words]
9. Online Talking Dictionary: [293864 words]
10. Free Dictionary: [254453 words]
11. Rhymezone: [229780 words]
12. LookWAYup Translating Dictionary/Thesaurus: [187425 words]
13. AllWords.com Multi-Lingual Dictionary: [175063 words]
14. Mnemonic Dictionary: [147153 words]
15. Infoplease Dictionary: [127110 words]
16. WordNet 1.7 Vocabulary Helper: [119160 words]
17. Urdu/English Dictionary: [113319 words]
18. Online Plain Text English Dictionary: [111729 words]
19. Merriam-Webster’s Online Dictionary, 11th Edition: [107545 words]
20. Encarta® World English Dictionary, North American Edition: [107301 words]
21. UltraLingua English Dictionary: [103294 words]
22. Cambridge International Dictionary of English: [92986 words]
23. American Heritage Dictionary of the English Language: [90491 words]
24. Webster’s Revised Unabridged, 1913 Edition: [88773 words]
25. Eurodict Online: [81035 words]
26. Webster’s New World College Dictionary, 4th Ed.: [80134 words]
27. Webster’s 1828 Dictionary: [62949 words]
28. Logos Multilingual E-translation Portal: [60678 words]
29. Langtolang: [51081 words]
30. Columbia Encyclopedia, Sixth Edition: [50831 words]
31. The Free Dictionary: [49963 words]
32. Gaelic Language (Manx): [48957 words]
33. The Free Dictionary: [48752 words]
34. The Wordsmyth English Dictionary-Thesaurus: [47719 words]
35. Macmillan Dictionary: [46109 words]
36. Compact Oxford English Dictionary: [41947 words]
37. Cambridge Dictionary of American English: [37791 words]
38. Collins Pocket English Dictionary: [37476 words]
39. 1911 edition of the Encyclopedia Britannica: [33710 words]
40. Columbia Gazetteer of North America: [33247 words]
41. The Free Dictionary: [28043 words]
42. Stammtisch Beau Fleuve Acronyms: [24060 words]
43. The Free Dictionary: [23996 words]
44. The Free Dictionary: [22814 words]
45. Online Etymology Dictionary: [21462 words]
46. General English-Spanish: [20735 words]
47. Langtolang English from/to French dictionary: [20075 words]
48. The Phrontistery – A Dictionary of Obscure Words: [16690 words]
49. Hutchinson Dictionaries: [15195 words]
50. Dictionary of Phrase and Fable (1898): [15100 words]
51. Hutchinson’s Dictionary of Difficult Words: [14455 words]
52. Cobuild Student Dictionary for Learners of English: [13410 words]
53. 18 LANGUAGES MULTILINGUAL DICTIONARY: [9103 words]
54. Luciferous Logolepsy: [9029 words]
55. Columbia Encyclopedia, Sixth Edition (Encyclopedia.com): [7267 words]
56. Wikimedia Commons US English Pronunciations: [7192 words]
57. The New Dictionary of Cultural Literacy: [6639 words]
58. Virdainas – a Sudovian Dictionary: [5920 words]
59. The Free Dictionary: [5417 words]
60. E Cobham Brewer, The Reader’s Handbook: [5272 words]
61. Faclair G?idhlig – Beurla Gaelic – English Dictionary: [5173 words]
62. Cambridge International Dictionary of Idioms: [5132 words]
63. Typographical Errors in Library Databases: [5114 words]
64. Encarta® Online Encyclopedia, North American Edition: [4994 words]
65. Who2: [4331 words]
66. Worthless Word For The Day: [4234 words]
67. InfoVisual Visual Dictionary: [3884 words]
68. R-O-Matic Italian/English Dictionary: [3504 words]
69. The Word Spy: [2701 words]
70. MyWord.info: [2507 words]
71. Japanese Kanji & Chinese Calligraphy Dictionary: [2420 words]
72. GREEK-ENGLISH DICTIONARY: [2403 words]
73. World Wide Words: [2363 words]
74. Dictionary of Americanisms (1848): [2158 words]
75. V2 Vocabulary Building Dictionary: [2042 words]
76. Grandiloquent Dictionary: [2039 words]
77. Cambridge International Dictionary of Phrasal Verbs: [1929 words]
78. Strange and Unusual Dictionaries: [1769 words]
79. The Word Detective: [1599 words]
80. All About Homonyms: [1506 words]
81. Double-Tongued Word Wrester: [1269 words]
82. Bali: The Online Travel Guide: [978 words]
83. My Hebrew Dictionary: [974 words]
84. Phrase Finder: [939 words]
85. UVic Writer’s Guide: [759 words]
86. A to Z list of the most popular idioms: [433 words]
87. ESL Idiom Page: [401 words]
88. Britih-American Dictionary: [365 words]
89. American-Britih Dictionary: [362 words]
90. The Spoken Taino Language: [334 words]
91. Yiddish-Hebrew-English-German-Russian Picture Dictionary: [186 words]
92. Phrasal Verb Page: [173 words]
93. Robb: German English: [160 words]
94. Russian dictionary: [157 words]
95. Turkish Acronyms to live by: [138 words]
96. Celtic Dictionary: [129 words]
97. New English Words: [113 words]
98. Foreign Words and Phrases: [73 words]
99. Election glossary: [61 words]
100. Ye Olde English Sayings: [43 words]

• American Heritage – Fourth edition has 90,000+ entries.
• Cambridge Dictionaries – Includes phrases and idioms.
• Dictionary.com – Definitions from Webster’s and more.
• Merriam-Webster – Familiar, fast and easy dictionary.
• OneLook Dictionaries – Search many dictionaries at once.
• World English Dictionary – Includes audio pronunciations.
• yourDictionary.com – Dictionaries for 230+ languages.
• Glossarist.com – A Glossary directory to 20 topics.