explain vs overstate

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. 

overstate

verb
  • To exaggerate; to state or claim too much. 

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