Dictionary -- Thesaurus-- Atlas--Almanac

Merriam-Webster Dictionary and Thesaurus
This dictionary has excellent definitions. It is better than dictionary.com.

Learner's Dictionary
This one is good for English Language Learners and anyone who wants a concise word definition.

Visual Dictionary
This is a different way to look up a word. Use this dictionary "when you know what something looks like but not what it’s called, or when you know the word but can’t picture the object, The Visual Dictionary has the answer. In a quick look, you can match the word to the image."

World Atlas
This online atlas includes geography facts, flags, symbols, time, currency, and more.

Etymology Dictionary
Use this dictionary to find the origins of words.

Fact Monster
Use this website as an online almanac, atlas, dictionary, or encyclopedia.
It also has Cool Stuff and Games & Quizzes