polymorphic vs protean

polymorphic

adj
  • Relating to polymorphism (any sense), able to have several shapes or forms. 

  • Having or relating to the ability to take multiple data types for a single parameter. 

  • Relating to a compound that can crystallizes into two or more distinct forms (e.g. carbon, which can crystalize into coal, graphite, diamond, etc.) 

protean

adj
  • Exceedingly variable; readily assuming different shapes or forms. 

noun
  • A protein that has been slightly modified by water, dilute acid, or enzymes, but not modified to the extent of a metaprotein. 

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