Lingoes is a free dictionary ( desktop application ) and It is the best dictionary you can find. Calling it just a dictionary would be wrong actually because it includes :

• Search as you type in feature for word meaning with 80 language support
• Embedded speech engine.
• 14 Language Translation engines.
• Supports inline find i.e. Select any word in your browser or a file and press ctrl + right click and you would see the meaning of it.
• You can also enable real time pronunciation when you look up for a word.

Supported Langauge : English, French, German, Spanish, Italian, Russian, Chinese, Japanese, Korean, Swedish, Thai, Turkish, Vietnamese, Greek, Polish, Arabic, Hebrew and more over 80 languages.

Dictionary search with translation and speech

Impressive Search Result

The best part comes when you do a search on a word and you get results from 3-4 dictionary sites including from Google. This makes it easier for you to hunt down a word and find more related information on this.

Dictionary search result from Online Dictionaries and Search Engines

Find meanings with just a right click

Dictionary inline search support

You can check the main web site of Lingoes and download the free dictionary. You can also add additional dictionaries if you want.