foray vs onrush

foray

verb
  • To participate in a foray. 

  • To do or attempt something outside one's typical area of expertise. 

noun
  • A brief excursion or attempt, especially outside one's accustomed sphere. 

  • A sudden or irregular incursion in border warfare; hence, any irregular incursion for war or spoils; a raid. 

onrush

verb
  • To rush or flow forward forcefully. 

  • To assault aggressively. 

noun
  • An aggressive assault. 

  • A forceful rush or flow forward. 

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