explain vs psych out

explain

verb
  • To make something plain or intelligible. 

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

  • To give a valid excuse for past behavior. 

psych out

verb
  • To outsmart. 

  • To unnerve. 

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