How to sign: the series of vertebrae forming the axis of the skeleton and protecting the spinal cord
"the fall broke his back";
Similiar / Same: spinal column, vertebral column, spine, rachis, back
Categories: skeletal structure
Within this category: chine, notochord
How to sign: the part of a network that connects other networks together
"the backbone is the part of a communication network that carries the heaviest traffic";
Categories: connecter, connection, connective, connector, connexion