Google have been killing off their older custom search engines for the past several months, and this week the dictionary search engine went up on the chopping block.
For those who never used it, there used to be a special page at Google .com/dictionary that you could use to look up definitions. It only pulled results from dictionary and thesaurus websites.
I'm surprised it hung around this long. I can't tell you how many years it has been since I last used it. I've found it to be much faster to just google "define word". That's seven extra keystrokes vs waiting for another page to load.
Like the other redundant search engines, pretty much all of the functionality of the dictionary page can be found on the Google homepage. But if you're pining for the lost page, there are alternatives. There are Chrome and Firefox plug-ins that specialize in definitions and you can add a dictionary specific search engine to the search window in the upper right corner of your browser.