A recreant is a heavy-duty coward. If your friend shoves you in front of him when a growling dog approaches, you'd quickly recognize him for the recreant that he is. And in the future you’d choose your friends more carefully.
An extreme recreant would be the soldier who goes over to the enemy if it looks like they might win. Definitely not the kind of person you'd want in your platoon. Recreant (RE-cree-unt) comes from the Latin re-, meaning to "reverse" something, and credere, "entrust." The word miscreant is nearly synonymous, although a miscreant is not so much a coward, but just an all-around bad sort.