Wikipedia got its search engine called WikiSeek. Only websites refered in Wekepedia are searchable through the WikiSeek. Wikipedia probably hosts a lot of information rich websites, but to think that all of the good sites are there or will be there is limiting. WikiSeek is good only for searching Wikipedia, if you want more precise Internet information move to a better search engine.
At the same time two graduates from Columbia University created MetaGlossary, a search service which defines more than 2 million terms, phrases, acronyms, and all kinds of difficult words. Google also offers similar feature. If you type " define: " followed by the word you want to be explained, you will automatically get a definition, if one is available on the Internet.
After a couple of experiments between Google's "define" feature and MetaGlossary I have to say that usually Google lists more results and offers translation of defined terms in other languages, but I still like MetaGlossary for their simple short and well explained results. After all who has the time to read 28 definition of "APR" on Google.
Via: Search Engine Land