If you use the WordPress plugin SEO SearchTerms Tagging 2 for the purpose of displaying incoming search terms and search phrases, it is highly likely that Google is going to see this as keyword stuffing. In other words, you are placing multiple, similar keyword phrases on your page for no obvious purpose other than trying to trick the search engines into liking your posts.
SEO is changing. Experts will tell you that it was always about good original content. But there used to be ways to encourage search engines to add relevance to your posts even if your content wasn’t that good. These ‘loopholes’ are being closed. Search engines are becoming smarter and are better able to recognise "good original content. And they are learning to ignore and even penalise what they see as attempts to trick them.
It may have its uses in the admin panel to let you know what people are searching for.
I hope it will help you alot.