demountable vs severable

demountable

adj
  • Able to be removed from its mount; designed to be dismantled. 

noun
  • A temporary and portable building, especially a portable classroom in a school. 

severable

adj
  • Capable of being severed. 

  • Capable of being separated. 

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