1. VocabSushi: - http://vocabsushi.com

VocabSushi lets you build your vocabulary by providing the definition, pronunciation and usage of thousands of words. They also have word lists to prepare you for standardized tests like GRE, SAT and ACT. Moreover, you can also do sentence completion exercises and download MP3s to learn new words on the go.

2. Idiom Site: - http://www.idiomsite.com

Do you feel a bit lost when somebody mentions phrases like Peeping Tom, Know the Ropes or Excuse my French? May be you should check out the IdiomSite. IdiomSite is a collection of hundreds of idioms along with their explanations. All the idioms are in alphabetical order so it is easy to jump to a certain idiom you are looking for.

3. Symbols: - http://symbols.com

If symbols baffle you, Symbols.com is an excellent resource to look up symbols, see what they mean and when/how were they introduced. You can browse through the Graphic Index or a Word index to find symbols.

4. Word Spy: - http://www.wordspy.com

WordSpy is your guide to new words. It features words and terms that are being introduced in the english language. WordSpy also explains what the term means and how to sue it in context. So if you ever wonder what words like CarrotMob and Intexicated mean, WordSpy is the place to go.

5. RhymeZone: - http://www.rhymezone.com

In English language there is no rhyming word for Orange. Except that, you can find rhyming words for any word on RhymeZone.com In addition to rhyming words, RhymeZone also lets you find synonyms, antonyms and homophones for the words of your choice.

6. SaveTheWords: - http://www.savethewords.org

SaveTheWords is an effort to prevent words from going extinct. It is a large collection of old words that are seldom used nowadays. You can see the definition of each word and see how it is used in a sentence. If you feel a bit moved, you can even adopt a word by promising to use it in your conversations and correspondence.

7. Confusing Words: - http://www.confusingwords.com/index.php

If you have ever been confused between effect/affect or affluent/effluent, you will like ConfusingWords.com It is a collection of over 3000 words that usually confuse people. Confusing Words explains the pair of words and describe their usage in proper context.

8. TipOfMyTongue: - http://chir.ag/projects/tip-of-my-tongue

Find the words you are trying to speak. Words that are on the tip of your tongue but aren’t coming out. TipOfTheTongue is a cool tool that allows you to look for such words by entering as little or as much information you have about the words.

9. Acronym Finder: - http://www.acronymfinder.com

Acronym finder tells you what each abbreviation stands for and what does it mean. If there are multiple acronyms, they are assigned categories and a single click lets you search that acronym in Google.

10. Thesaurus: - http://www.ironicsans.com/thsrs

There are hundreds of websites that would give you synonyms of a word, but only Thsrs will provide you with a shorter synonym of any word. You can also install it as a FireFox Add-On for easier access.

11. How j say: - www.howjsay.com

See how any word of English language is pronounced. Howjsay is a very simple and neat tool to learn how to say a certain word. You can also translate the word in any foreign language with a single-click.

12. VisuWords: - www.visuwords.com

VisuWords is probably the best tool if you want to understand a word and see how it works. In addition to the definition, VisuWords also create a visual mashup to provide various other attributes and relations of the word. Each attribute is highlighted with a different color and a legend on the side explains what each color denotes.