"To see a definition for a word or phrase, simply type the word "define," then a space, and then the word(s) you want defined. If Google has seen a definition for the word or phrase on the Web, it will retrieve that information and display it at the top of your search results.
You can also get a list of definitions by including the special operator "define:" with no space between it and the term you want defined. For example, the search [define:World Wide Web] will show you a list of definitions for "World Wide Web" gathered from various online sources."
"WordWeb Pro is a quick and powerful international English thesaurus and dictionary for Windows. It can be used to lookup words from almost any Windows program, showing definitions, synonyms and related words. There are also many proper nouns and usage examples. You can search for words matching a pattern, find and solve anagrams, and optionally search a large number of extra word lists."