delineate vs expound

delineate

verb
  • To describe or depict with words or gestures. 

  • To outline or mark out. 

  • To depict, represent with pictures. 

  • To sketch out, draw or trace an outline. 

expound

verb
  • To set out the meaning of; to explain or discuss at length 

  • To make a statement, especially at length. 

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