backboneless vs chickenshit

backboneless

adj
  • Cowardly, spineless. 

  • Without a backbone; invertebrate. 

chickenshit

adj
  • cowardly 

  • petty and contemptible; contemptibly unimportant. (Compare bullshit.) 

noun
  • A low-ranking officer who lords over and needlessly makes life miserable for his underlings; a petty, abusive martinet. 

  • (A) petty and contemptible thing(s). 

  • coward 

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