assault vs fall on

assault

verb
  • To attack, physically or figuratively; to assail. 

  • To threaten or harass. 

noun
  • A non-competitive combat between two fencers. 

  • A violent onset or attack with physical means, for example blows, weapons, etc. 

  • A violent verbal attack, for example with insults, criticism, and the like 

  • An act that causes someone to apprehend imminent bodily harm (such as brandishing a weapon). 

  • An attempt to commit battery: a violent attempt, or willful effort with force or violence, to do hurt to another, but without necessarily touching the person, such as by raising a fist in a threatening manner, or by striking at the person and missing. 

  • The tort whose action is such an act. 

  • The crime whose action is such an attempt. 

fall on

verb
  • To experience; to suffer; to fall upon. 

  • To be assigned to; to acquire a new responsibility, duty or burden. 

  • To occur on a particular day. 

  • Of the eyes or gaze: to alight upon. 

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