conceal vs delineate

conceal

verb
  • To hide something from view or from public knowledge, to try to keep something secret. 

delineate

verb
  • To outline or mark out. 

  • To describe or depict with words or gestures. 

  • To depict, represent with pictures. 

  • To sketch out, draw or trace an outline. 

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