Wiktionary:Other dictionaries on the Web

About

The dictionaries which are listed here should

not include any neural machine translation tools like Google Translate.
be correctly written and classified.
not be malicious or phishing.

This is not a policy but a guideline

English

Cambridge Dictionary Online
Dictionary.com
Fine Dictionary
The Free Dictionary
HyperDictionary - includes Webster's Dictionary, 1913
LexiCool
Longman Dictionary of Contemporary English
Merriam-Webster Online - American English as main entries, also includes British English as 'See-also' entries. Dictionary and thesaurus.
- See also Wiktionary:Merriam-Webster
Memidex - WordNet-based dictionary/thesaurus with definition, audio, and etymology references
OneLook Dictionary Search - searches many others - including Wiktionary, great for American and British English, checking spellings, wild cards (e.g. searching for words containing definitions and crossword-type stuff like searching for words spelled C_M_N) and definitions. Dictionary and thesaurus.
Oxford Dictionaries
WordNet - a lexical database for English
Wordnik
WordReference
World English Historical Dictionary
World Wide Words
YourDictionary

General Public License dictionaries

GNU version of The Collaborative International Dictionary of English (GCIDE)

Public domain dictionaries

See also: Wiktionary:Public domain sources

Slang

Texting Abbreviations List. Textspeak dictionary.
British Internet Slang Dictionary by Ted Duckworth
NoSlang - Internet Slang Dictionary & Translator
SlangLang - Online dictionary for slang words
Urban Dictionary - user-generated content, with an enormous database of genuine slang but also made-up-and-used-by-one-person crap.

Jargon

FOLDOC - Free On-Line Dictionary of Computing
NetLingo - The Internet Dictionary of Computer and Internet Terms

Other languages

Translations to/from English

AllWords
The Compleat Lexical Tutor - free tools
Ethnologue: Languages of the World
ForeignWord
FreeTranslation
Glosbe: Bilingual dictionaries hub, over 100 languages
Linguee - search 100 million translations (German)
Translation.net - free instant translation from Systran
Larousse
dict.cc

Catalan

Diccionari de la llengua catalana

Chinese

MDBG English to Chinese dictionary - interface to CEDICT, a Chinese-English electronic dictionary with Mandarin pinyin
CC-Canto - Cantonese dictionary based on CEDICT
MOEdict - interface to several online dictionaries: Mandarin, Min Nan, Hakka dictionaries from the Ministry of Education (Taiwan), a cross-strait dictionary from the General Association of Chinese Culture. Translations from the CC-CEDict (Chinese–English), CFDict (Chinese–French) and HanDeDict (Chinese-German) are also included in entries.
Multi-function Chinese Character Database - a professional single character based dictionary provided by CUHK
粵音資料集叢 - Cantonese pronunciation with multiple sources
Han Dian
Zitong Web - professional dictionary on Hanzi

Classical Chinese

Wenyan Wen Zidian

Czech

UPJC

Danish

Den Danske Ordbog - current language; maintained by w:Dansk Sprog- og Litteraturselskab
Ordbog over det danske Sprog - covers the period 1700-1950; also published by DSL
Nye Ord i Dansk - a dictionary of recent additions to Danish; also maintained by DSN

Dutch

Middle Dutch

Historische woordenboeken

Esperanto

Reta Vortaro

Faroese

Orðalistar - an array of topical word lists, some Danish-Faroese, some English-Faroese, some monolingual; published by Føroyska Málráðið, the Faroese Language Council
Føroysk orðabók - published by Orðabókagrunnurin, the Dictionary Association

French

German

Digitales Wörterbuch der Deutschen Sprache
Duden - grammatical information, synonyms, pronunciation and more
Wörterbuchnetz
Leo

Greek

Practical Dictionary of the Modern Greek Language

Greenlandic

Katersat - Greenlandic/Danish/English. Some (most?) derived words have their composition given, and most have plural and relative forms and pronunciation. Affixes are listed independently, but there seem to be some lacking.
DAKA - published by Ilinniusiorfik (Greenlandic/Danish). According to this, it is a combination of earlier works Oqaatsit and Ordbogen.
Greenlandic English Dictionary - published by Oqaasileriffik, the Greenland Language Secretariat; downloadable spreadsheet (Greenlandic to English/Danish); includes both new and old orthography; still in progress.

Japanese

Jisho.org - online interface to several electronic Japanese–English dictionaries like EDICT, JMnedict, etc.
kotobank.jp - free access to the monolingual Daijirin, Daijisen, an encyclopedia, and a Japanese-English dictionary.
weblio.jp - ditto, with dictionaries of many specific domains.
dictionary.goo.ne.jp
eow.alc.co.jp - a Japanese–English dictionary

Latin

Latdict

Scottish Gaelic

An Etymological Dictionary of the Gaelic Language

Spanish

Real Academia Española - It has two Spanish monolingual dictionaries: "Diccionario de la lengua española" and "Diccionario panhispánico de dudas"

Turkish

Welsh

A pocket dictionary - It has about 25k one-line Welsh entries with English definitions, e.g. "Ystyriaethu, v. to use consideration or reflection" Proofreading is still in progress.