symbiotic vs usable

symbiotic

noun
  • symbiotic star 

adj
  • Of, or relating to symbiosis; living together. 

  • Of a relationship with mutual benefit between two individuals or organisms. 

usable

adj
  • Easy to use; exhibiting good usability. 

  • homosexual 

  • Capable of being used. 

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