Dictionaries:
Abbreviations: Browse the Web's Largest Acronyms & Abbreviations Resource
http://www.abbreviations.com/
Acronyms: Find out what any acronym, abbreviation, or initialism stands for
http://www.acronymfinder.com/
Dictionary:
http://dictionary.reference.com/
Dorland's Illustrated Medical Dictionary:
http://www.dorlands.com/
Etymonline Dictionary: Explanations of what our words meant and how they sounded 600 or 2,000 years ago
http://www.etymonline.com/
Merriam -Webster:
http://www.merriam-webster.com/
OneLook Dictionary Search:
http://www.onelook.com/
Rhyming Dictionary:
http://rhymezone.com/
Slang Dictionary:
http://www.urbandictionary.com/
Thesaurus:
http://thesaurus.com/
Abbreviations: Browse the Web's Largest Acronyms & Abbreviations Resource
http://www.abbreviations.com/
Acronyms: Find out what any acronym, abbreviation, or initialism stands for
http://www.acronymfinder.com/
Dictionary:
http://dictionary.reference.com/
Dorland's Illustrated Medical Dictionary:
http://www.dorlands.com/
Etymonline Dictionary: Explanations of what our words meant and how they sounded 600 or 2,000 years ago
http://www.etymonline.com/
Merriam -Webster:
http://www.merriam-webster.com/
OneLook Dictionary Search:
http://www.onelook.com/
Rhyming Dictionary:
http://rhymezone.com/
Slang Dictionary:
http://www.urbandictionary.com/
Thesaurus:
http://thesaurus.com/
Encyclopedias/Fact Sites:
Data.gov: Increases the ability of the public to easily find, download, and use datasets that are generated and held by the Federal Government.
http://www.data.gov/
Encyclopedia:
http://www.encyclopedia.com/
ERIC: Education Resources Information Center:
http://eric.ed.gov/
Info please:
http://www.infoplease.com/
SFE: The Enclyclopedia of Science Fiction
http://www.sf-encyclopedia.com/
World Factbook:
https://www.cia.gov/library/publications/the-world-factbook/index.html