The WordWeb English dictionary and thesaurus: fast searching, spelling suggestions, definitions, usage examples, synonyms, related words - and no adverts.
The intelligent word entry suggests possible correct spellings as you type, as well as listing words that sound the same or are often confused.
Additional features include the ability to drill down on any word in a definition, full bookmark support and history.
No Internet connection is required to use WordWeb, and it's free!
For one-click look up in any program and audio pronunciations, get the WordWeb desktop program from the wordweb.info website instead.