immovable vs nonnegotiable

immovable

noun
  • that which can not be moved; something which is immovable 

adj
  • steadfast in purpose or intention; unalterable, unyielding 

  • not capable of being affected or moved in feeling; impassive 

  • not liable to be removed; permanent in place or tenure; fixed 

  • incapable of being physically moved; fixed 

nonnegotiable

noun
  • Something that is not negotiable. 

adj
  • Not negotiable; not subject to negotiation. 

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