collusive vs symbiotic

collusive

adj
  • secretly acting together for a fraudulent or illegal purpose 

symbiotic

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

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

noun
  • symbiotic star 

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