explain vs outline

explain

verb
  • To make plain, manifest, or intelligible; to clear of obscurity; to illustrate the meaning of. 

  • To give a valid excuse for past behavior. 

  • To make something plain or intelligible. 

outline

verb
  • To draw an outline of. 

  • To optimize for size by replacing repeated code fragments with function calls. 

  • To summarize. 

noun
  • A line marking the boundary of an object figure. 

  • The outer shape of an object or figure. 

  • A prose telling of a story intended to be turned into a screenplay; generally longer and more detailed than a treatment. 

  • A sketch or drawing in which objects are delineated in contours without shading. 

  • A general description of some subject. 

  • A preliminary plan for a project. 

  • A statement summarizing the important points of a text. 

  • A setline or trotline. 

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