If you're working on a document in Word, Excel or PowerPoint 2016 and you're not sure about using a word or reference or particular terminology, stay in the program and try out Smart Lookup:
Highlight the word, right click and select Smart Lookup.
Highlight the word, click Review on the menu and then Smart Lookup.
The Insights panel will open on the right displaying related web search results in the Explore tab. Click on any of the results to open the webpage with related information. (Note that on the Mac, you may see an initial screen informing you that your highlighted term will be sent to Bing, the Microsoft search site. To continue, click Got it.)
You can also click on the Define tab to learn the definition, synonyms and sometimes origin of the word, along with how to pronounce it.