Google has launched its own dictionary, Google Dictionary, and already integrated it into their search results.
First discovered by the LATimes, the new dictionary is available from your Google search results by clicking the [definition] link or directly via www.google.com/dictionary.
In addition to Google's own database of definitions the service provides a list of definitions from the web. You can even star words for access at a later date similar to the star feature of Google Reader as well as view a list of recent searches.
Previously, the [definition] link was directed to Answers.com which will likely suffer substantial traffic loss due to the change.