The term 'CHICKEN's Lack' can be solved by the crossword solutions NERVE (5 letters), SPINE (5 letters), and LIPS (4 letters). Chickens, like other animals, have a nervous system that is composed of nerves, which are bundles of fibers that transmit signals throughout the body. The SPINE is the backbone of the CHICKEN, providing support and protection for the internal organs. Finally, chickens do not have LIPS, as they lack the facial muscles necessary to form them.