backbone

noun

1. a central cohesive source of support and stability

   noun.cognition

   Synonyms anchor keystone linchpin lynchpin mainstay

   Source: WordNet 3.0

2. fortitude and determination

   noun.attribute

   Synonyms grit gumption guts moxie sand

   Source: WordNet 3.0

3. the series of vertebrae forming the axis of the skeleton and protecting the spinal cord

   noun.body

   Synonyms back rachis spinal column spine vertebral column

   Source: WordNet 3.0

4. the part of a book's cover that encloses the inner side of the book's pages and that faces outward when the book is shelved

   noun.artifact

   Synonyms spine

   Source: WordNet 3.0

5. the part of a network that connects other networks together

   noun.artifact

   Examples

   The backbone is the part of a communication network that carries the heaviest traffic.

   Source: WordNet 3.0

6. The column of bones in the back which sustains and gives firmness to the frame; the spine; the vertebral or spinal column.

   noun

   Source: webster1913