backbone vs wald

backbone

noun
  • Courage, fortitude, or strength. 

  • The series of vertebrae, separated by disks, that encloses and protects the spinal cord, and runs down the middle of the back in vertebrate animals. 

  • Any fundamental support, structure, or infrastructure. 

wald

noun
  • Power; strength. 

  • Command; control; possession. 

  • Forest; woods. 

verb
  • To govern; inherit. 

How often have the words backbone and wald occurred in a corpus of books? (source: Google Ngram Viewer )