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Dictionary.com strives to enable and inspire connection, communication, learning, creativity, and expression in a world powered by words.

The world’s largest and most trusted free online thesaurus brought to you by Dictionary.com.

For more than 150 years, in print and now online, Merriam-Webster has been America's leading and most-trusted provider of language information.

Search more than 275,000 synonyms, antonyms, related words, and idiomatic phrases. Find concise definitions pinpointing the meaning shared by synonyms, and sample sentences showing how words are used in context. The thesaurus is more than just a list of synonyms; it is your guide to more precise and effective use of language.

Cambridge University Press has been publishing dictionaries for learners of English since 1995. Cambridge Dictionaries Online began offering these dictionaries completely free of charge in 1999 — and today, Cambridge Dictionary is still growing.

Collins is a major publisher of Educational, Language and Geographic content, and have been publishing innovative, inspiring and informative books for over 200 years.

Collins English Thesaurus is a comprehensive, trustworthy and easy-to-use online resource, and has been researched and written by experienced lexicographers from across the globe and reflects all varieties of world English.

Over 19,000 biographies of significant, influential or notorious figures from American history written by prominent scholars

Biography.com captures the most gripping, surprising and fascinating stories about people. The last fateful day. The decision that changed everything. The moment of cheating death. The biggest break. The defining opportunity. The most shattering failure.

Biographies.net is a huge collection of biographies about famous and not-so-famous individuals, including a large amount of facts, birthday information, life story, profession, family and more - collaboratively assembled by contributing editors.

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. Combined with the Acronym Attic, Acronym Finder contains more than 5 million acronyms and abbreviations.

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 and it is maintained and expanded by a large community of passionate editors.

Encyclopedia.com provides you reference entries from credible, published sources like Oxford University Press and Columbia Encyclopedia.At Encyclopedia.com, you get free access to over 300,000 reference entries from sources you can cite. Plus, more than 50,000 topic summaries feature related pictures, videos, topic summaries, and newspaper and magazine articles from around the world.

Containing over 100,000 terms, TheFreeDictionary's Encyclopedia is compiled from a number of sources, including The Columbia Encyclopedia®. The current Columbia Electronic Encyclopedia® contains nearly 52,000 entries and more than 84,000 hypertext cross-references, marshalling 6.5 million words on a vast range of topics.

Encyclopedia Mythica is an internet encyclopedia on mythology, folklore, and religion.
Everything from Aaron to Zygius, with thousands of articles in between.

A non-profit organization publishing the world's most-read history encyclopedia with the mission to engage people with cultural heritage and to improve history education worldwide.

Access more than 57,000 articles from the Columbia Encyclopedia, Sixth Edition.

The World Factbook provides basic intelligence on the history, people, government, economy, energy, geography, environment, communications, transportation, military, terrorism, and transnational issues for 266 world entities.

Convert.net is an online conversions calculator for a variety of unit measurements featuring natural language queries.
You can use Convert.net to sum up a list of numbers, convert from pounds to kilograms, or evaluate any other mathematical expression.

Click on a region to view images and animations for that region. Coverage area depictions are approximate.

NOAA's National Centers for Environmental Information (NCEI) is responsible for preserving, monitoring, assessing, and providing public access to the Nation's treasure of climate and historical weather data and information.

Contains the electronic versions of 80 books previously published in hard copy as part of the Country Studies Series by the Federal Research Division. Intended for a general audience, books in the series present a description and analysis of the historical setting and the social, economic, political, and national security systems and institutions of select countries throughout the world.

Whitepages is the authority in people search, established in 1997. With comprehensive contact information, including cell phone numbers, for over 275 million people nationwide, and Whitepages SmartCheck, the fast, comprehensive background check compiled from criminal and other records from all 50 states.

Calculations and conversations of different type of items.