embattle vs entrench

embattle

verb
  • To prepare or arm for battle; to equip as for battle. 

  • To arrange in order of battle; to array for battle. 

  • To be arrayed for battle. 

  • To furnish with battlements; to give the form of battlements to. 

noun
  • A merlon, or a single one of the series of solid projections of a battlement. 

entrench

verb
  • To surround or provide with a trench, especially for defense; to dig in. 

  • To establish a substantial position in business, politics, etc. 

  • To dig or excavate a trench; to trench. 

  • To invade; to encroach; to infringe or trespass; to enter on, and take possession of, that which belongs to another; usually followed by on or upon. 

  • To cut in; to furrow; to make trenches in or upon. 

  • To become completely absorbed in and fully accept one's beliefs, even in the face of evidence against it and refusing to be reasoned with. 

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