air raid vs ambush

air raid

noun
  • An attack on a surface target by aircraft. 

  • A passing-heavy offensive scheme based on a shotgun formation with four wide receivers and a single running back. 

ambush

noun
  • An attack launched from a concealed position. 

  • The act of concealing oneself and lying in wait to attack by surprise. 

  • The concealed position or state from which a surprise attack is launched. 

  • The troops posted in a concealed place, for attacking by surprise; those who lie in wait. 

verb
  • To station in ambush with a view to surprise an enemy. 

  • To attack by ambush; to waylay. 

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