I'm guessing the chicory root you wish to substitute was itself a substitute for coffee.... yes? If so, there are numerous options, including a pretty good date-based coffee I've tatsed recently. I can send you the link if that's what you had in mind.

SKK is right. It's difficult to answer your question without knowing what the application is where you would like to substitute it.

The chickory root is related to endive and raddichio, and can be eaten when boiled.
Chickory leaves can be used in salad, and of course you know chickory is a substitute for coffee with health benefits. Don't have an answer, not knowing your recipe. Hope this helps.