Google announced on Google+ that they have overhauled the Web definitions interface and results, adding a lot more meat and details to your definitions queries.
The new options include an expandable box that contains additional synonyms, ways to use the word in sentences, the origins of the word, translation, the use of the word over time and much more. Also, when translate the word within, future definition searches will consistently provide a translation to that same language
Here is a screen shot of it in action:
Google said on Google+:
You may be familiar with using Google to find definitions, like [define fortuitous]. We’ve recently updated this feature on google.com on desktop and mobile to give you more information about these words beyond just their definition. Now you’ll also see sample sentences that highlight how the word is used, as well as synonyms. If you tap the microphone on your Google Search app, you’ll hear answers spoken back when you ask questions like “What’s the definition of fortuitous?” and “What are synonyms for fortuitous?”