Top 40 Best Free Online Dictionaries and Thesaurus

A DICTIONARY is collection of words in one or more specific languages, often listed alphabetically (or by radical and stroke for ideographic languages), with usage of information, definitions, etymologies, phonetics, pronunciations, translation, and other information; or a book of words in one language with their equivalents in another, also known as a lexicon. According to Nielsen (2008) a dictionary may be regarded as a lexicographical product that is characterised by three significant features: (1) it has been prepared for one or more functions; (2) it contains data that have been selected for the purpose of fulfilling those functions; and (3) its lexicographic structures link and establish relationships between the data so that they can meet the needs of users and fulfill the functions of the dictionary.

In general usage, a THESAURUS is a reference work that lists words grouped together according to similarity of meaning (containing synonyms and sometimes antonyms), in contrast to a dictionary, which provides definitions for words, and generally lists them in alphabetical order. The main purpose of such reference works is to help the user “to find the word, or words, by which [an] idea may be most fitly and aptly expressed” – to quote Peter Mark Roget, architect of the best known thesaurus in the English language. Although including synonyms, a thesaurus should not be taken as a complete list of all the synonyms for a particular word. The entries are also designed for drawing distinctions between similar words and assisting in choosing exactly the right word. Unlike a dictionary, a thesaurus entry does not give the definition of words.

Dictionary News, Reviews & Resources

• 10 words that don't mean what they used to - The Guardian.
• 11 words that make the heart sink - The Guardian.
• 21 Best New Words of 2016 - Wired.
• 28 WORDS THAT ONLY POSH PEOPLE USE - Tatler.
• 300 New Words Added to Scrabble Dictionary - "Scrabble enthusiasts will have 300 new words added to the Scrabble dictionary to up their game, thanks to the sixth edition of the popular board game."
• A critical period for second language acquisition - TIME Magazine.
• ACRONYM & INITIALISM - Wikipedia.
• business jargon we want to leave behind in 2017 - The Telegraph.
• Calvin Trillin on the Scariest Word - The New York Times.
• Can Duolingo's chatbot teach you a foreign language? - The Guardian.
• Come quick, the dictionaries are fighting - The Verge.
• DICTIONARY - Wikipedia.
• Emojipedia - since 2013. "Home of Emoji Meanings." The emoji search engine. A fast emoji search experience with options to browse every emoji by name, category, or platform.
• Enjoy Paris Without Letting Language Get in the Way - The New York Times.
• False friend - False friends are words in two languages that look or sound similar, but differ significantly in meaning.
• GLOSSARY - Wikipedia.
• Google improves Translate with offline AI - engadget.
• Google Translate now lets you chat to anyone in a foreign language - The Telegraph.
• 'Have your cake & eat it' - & other office jargon we love to hate - The Telegraph.
• How a single comma can cost millions - "For most people, a stray comma isn’t the end of the world. But in some cases, the exact placement of a punctuation mark can cost huge sums of money."
• How Exercise Can Help You Recall Words - The New York Times.
• 'Hygge' has made it into the Oxford English Dictionary - BBC.
• INTERNET SLANG - Wikipedia.
• iTranslate’s new app gets us one step closer to simple, real-time translation - The Verge.
• Laurel or Yanny debate explained: why do some people hear a different word? - The Guardian.
• LEXICON - Wikipedia.
• Oxford Dictionary announces word of the year 2018 - "How Oxford Dictionaries' Word of the Year Sums Up the Cultural Moment."
• Oxford English Dictionary finds space for 1,000 new words - The Guardian.
• ‘Poor little snowflake’ – the defining insult of 2016
• 'Post-truth' named word of year by Oxford Dictionaries - The Guardian.
• SLANG - Wikipedia.
• So, Um, How Do You, Like, Stop Using Filler Words? - The New York Times.
• Swimming in Words With Oliver Sacks - "His love of language has a life of its own."
• The positive lexicography - "Welcome to the positive lexicography, an evolving index of 'untranslatable' words related to wellbeing from across the world's languages."
• THESAURUS - Wikipedia.
• Why Bilinguals Are Smarter - The New York Times.
• Why It's So Hard to Learn Another Language After Childhood - TIME Magazine.
• World's most difficult language? - CNN style.

Top 40 Best Free Online Dictionaries & Thesaurus

• A DICTIONARY OF SLANG - "Dictionary of English slang and colloquialisms of the U.K."
• ABBREVIATIONS.COM - "We are the world's largest and most comprehensive directory and search engine for acronyms, abbreviations and initialisms on the Internet. Abbreviations.com holds hundreds of thousands of entries organized by a large variety of categories from computing and the Web to governmental, medicine and business."
• ACRONYM FINDER - "With more than 1,000,000 human-edited definitions, Acronym Finder is the world's largest and most comprehensive dictionary of acronyms, abbreviations, and initialisms."
• ALL ACRONYMS - "2,980,000 Acronyms and Abbreviations. 2,520 Topics."
• BABYLON'S ONLINE DICTIONARY - Babylon's Online Dictionary is dedicated to serving you the finest selection of the dictionaries, glossaries and encyclopedias on the web: more than 1400 dictionaries. More than 75 languages. Search myriads of terms, expressions and phrases.
• BUSINESS DICTIONARY - "Over 20,000 terms. Clear. Concise. Comprehensive."
• COLLINS ENGLISH DICTIONARY - free online dictionaries.
• CREDO REFERENCE - "Smart Research Starts Here." Puts the world's best citable information at your fingertips. Find: encyclopedias, dictionaries, biographies, quotations, bilingual dictionaries, crossword solver, measurement conversions.
• DICTIONARY OF ENGLISH SLANG AND COLLOQUIALISMS
• FINANCIAL DICTIONARY - by Investopedia a Forbes company.
• HISTORICAL THESAURUS OF ENGLISH - contains almost 800,000 words from Old English to the present day arranged into detailed hierarchies.
• INTERNETSLANG.COM - Internet slang words, Internet dictionary.
• INTERNET SLANG ACRONYMS & ABBREVIATIONS - "15,089 Internet slang acronyms and abbreviations."
• INTERNET SLANG DICTIONARY & TRANSLATOR - "Confused by internet slang? Can't read a text message? Translate internet slang and acronyms."
• INVESTOPEDIA - financial dictionary.
• LECTRIC LAW LIBRARY - legal resources & definitions.
• LEGAL-EXPLANATIONS.COM - "Free legal resources in plain English." Legal-Explanations.com provides the very best in free legal resources written in plain English. Our website currently contains over 2,500 legal definitions and will be expanded in coming months to include a vast collection of legal resources.
• MACMILLAN DICTIONARY - "Free Englishline online dictionary and thesaurus."
• MEDICINE NET.COM - "We Bring Doctors' Knowledge to You."
• MERIAM-WEBSTER ONLINE - "Dictionary and Thesaurus."
• MODELLING TERMINOLOGY - "The terms used to describe various types of modeling and photography are often poorly defined. Such ambiguity can result in misunderstandings and uncomfortable situations for models, photographers, and other industry professionals. In an effort to clarify terms and reduce miscommunication, we have provided a list of terms which describe various types of modeling and photography, as well as various styles and states of dress."
• NETLINGO - "The Internet Dictionary." Acronyms, text message jargon & smileys.
• NINJAWORDS - "A really fast dictionary... fast like a ninja."
• ONLINE ETYMOLOGY DICTIONARY - "Etymologies are not definitions; they're explanations of what our words meant and how they sounded 600 or 2,000 years ago."
• ONLINE SLANG DICTIONARY - "American, English, and Urban slang."
• OXFORD DICTIONARIES - "Language matters."
• OXFORD ENGLISH DICTIONARY - "The definitive record of the English language." Discover the story of English. More than 600,000 words, over a thousand years.
• OXFORD LANGUAGE DICTIONARIES ONLINE - "The world's most trusted dictionaries." At Oxford we know what it's like to learn, study, and use languages, and this site is designed to support you every step of the way. Oxford Language Dictionaries Online provides you with authoritative, up-to-date translations of all the words and phrases you need, plus a wealth of tools and resources to help you learn and use language more effectively.
• QUORA - "A continually improving collection of questions and answers created, edited, and organized by everyone who uses it." By invitation only.
• STYLEPEDIA - "Mr Porter's Glossary of Men's Style."
• THE FREE DICTIONARY - "The world's most comprehensive dictionary: English, Spanish, German, French, Italian, Chinese, Portuguese, Dutch, Norwegian, Greek, Arabic, Polish, Turkish, Russian, Medical, Legal, and Financial Dictionaries, Thesaurus, Acronyms and Abbreviations, Idioms, Encyclopedia, a Literature Reference Library, and a Search Engine all in one!" 7,135,906,944 visitors served.
• THE FREE DICTIONARY LANGUAGE FORUMS - by The Free Dictionary.
• The Knot - "Jewish Weddings: Glossary of Terms."
• THE TECH TERMS COMPUTER DICTIONARY - "Free online dictionary of computer and technology terms."
• Thesaurus - "Synonyms, Antonyms, and Related Words." Contains more than 145,800 unique entries from three top sources: Collins Thesaurus of the English Language - Complete and Unabridged, The American Heritage Roget's Thesaurus, and WordNet.
• URBAN DICTIONARY - "The slang dictionary you wrote." 4,293,657 definitions written since 1999.
• USING ENGLISH.COM - a general English language site, specialising in ESL (English as a Second Language) with a wide range of resources for learners and teachers of English.
• WEBOPEDIA - "Online Tech Dictionary for IT Professionals."
• WIKTIONARY - "The free English dictionary." 3,869,170 entries with English definitions from over 1400 languages.
• WORD DOMINATION.COM - "Dominate in Any Word Game!" Select number of letters in the word, enter letters you have, and find words!
• Wordnik - since 2009. "All the words." Online English dictionary and language resource that provides dictionary and thesaurus content, some of it based on print dictionaries such as the Century Dictionary, the American Heritage Dictionary, WordNet, and GCIDE. Wordnik has collected a corpus of billions of words which it uses to display example sentences, allowing it to provide information on a much larger set of words than a typical dictionary.
• WORDREFERENCE DICTIONARIES - "I started this site in 1999 in an effort to provide free online bilingual dictionaries and tools to the world. The site has grown gradually ever since to become one of the most-used online dictionaries, and the top online dictionary for its language pairs of English-Spanish, English-French, English-Italian, Spanish-French, and Spanish-Portuguese. It is consistently ranked in the top 500 most-visited websites in the world and is a top 100 website in Spain, France, Italy and all of Latin America."
• YOUR DICTIONARY - "The Dictionary You Can Understand." Dictionary and thesaurus. YourDictionary is the easiest-to-use online dictionary. It is a dictionary you can understand with lots of tools to help you choose your words precisely, understand a word, avoid usage pitfalls and be confident in your use of words.