abet vs ambush

abet

verb
  • To support, countenance, maintain, uphold, or aid (any good cause, opinion, or action); to maintain. 

  • To incite; to assist or encourage by aid or countenance in crime. 

ambush

noun
  • 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. 

  • An attack launched from a concealed position. 

  • 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 abet and ambush occurred in a corpus of books? (source: Google Ngram Viewer )