Double blue lines in Word

How come whenever I type "able to" or "assuming" in word, I get these double blue lines below the word. They're not squiggly, so I assume they're not grammar errors. I googled it, but they only had support for single blue squiggly lines, and they were talking about style errors. I'm fairly certain I don't have a style error, and I just want it to go away because it really distracts me. Thanks for your help guys

OK, I found the reason why it's highlighting it. As @LPChip noted, it's just pointing out that it's kinda wordy. To fix it, I just right-clicked my word and selected the suggestion in the menu.

I was able to get rid of some of the double blue underlines by unchecking "wordiness" in the preferences. I went to Word-->Preferences-->Spelling & Grammar-->Settings button (under Grammar section) and unchecked Wordiness. It's still appearing for some other errors, but at least it's not appearing as much.