Microsoft Office 2016 has a handy new feature called Smart Lookup.
Powered by Bing, Smart Lookup can bring up word definitions, Wikipedia articles, or web search results from content within Office applications like Outlook, PowerPoint and Word.
Try it out.
Within Word highlight a word or phrase or press L, right click, and choose Smart Lookup. Once the tool is enabled, the highlighted term will appear in the Insights panel. The Insights panel contains an explore panel which reveals basic search results and a define panel that provides a definition.
Before using the new feature, you will be prompted to review the policy policy and click the big Got it button.