The term 'protective body covering' can be summarized by the crossword solution 'SKIN'. SKIN is the largest organ of the human body and serves as a protective barrier against environmental factors such as bacteria, viruses, and other pathogens. It also helps regulate body temperature and protect against dehydration. SKIN is composed of several layers, including the epidermis, dermis, and subcutaneous tissue. It is constantly regenerating and renewing itself, making it an essential part of the body's defense system.