chameleonic vs protean

chameleonic

adj
  • Resembling a chameleon: readily changing color or other attributes 

protean

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

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

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