I'm guessing most of the younger set know this already, but... I had no idea I could do this.
Use google now on tap to copy any text in any app on android
Google now on tap is an amazing tool that gets skipped by most users. If you're on android 6.0+, hold down on your home button (Keep holding it) to open up "google now on tap" and click the finger icon at the bottom of the screen to active the feature. You may have to scroll down some to see it. This one step from any screen gives you access to tons of other features. Personally my favorite the copy any text from anywhere on your phone, I mean literally... any text from any screen.
When you select a word or whole paragraph, you will automatically get the definition, option to search, copy, or share.
Google now on tap offers a lot more features too so take a look.
Some things it will do.
The 10 Coolest Google Now On Tap Tricks