flexible vs mulish

flexible

adj
  • Capable or being adapted or molded in some way. 

  • Capable of being flexed or bent without breaking; able to be turned or twisted without breaking. 

  • Willing or prone to give way to the influence of others; not invincibly rigid or obstinate. 

noun
  • Something that is flexible. 

mulish

adj
  • Characteristic of a mule; stubborn, obstinate, or intractable 

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