Microsoft Edge is a new web browser that is available across the Windows 10 device family. It is designed for Windows 10 to be faster, safer, and compatible with the modern Web.
Starting with Windows 10 build 17713, Microsoft added a new dictionary function in Microsoft Edge, so you can look up definitions for key words in Reading View, Books, and PDFs. You can then choose to have a word read aloud to you to hear the correct pronunciation or expand more details from the definition.
This tutorial will show you how to turn on or off showing definitions inline for Books, Reading View, and PDF files in Microsoft Edge for your account in Windows 10.