ammunition vs howitzer

ammunition

verb
  • To supply with ammunition. 

noun
  • Articles used in charging firearms and ordnance of all kinds; as powder, balls, shot, shells, percussion caps, rockets, etc. 

  • Arguments and information that can be used against the other party in a conflict. 

howitzer

verb
  • To attack with a howitzer. 

noun
  • A cannon that combines certain characteristics of field guns and mortars, delivering projectiles with medium velocities, usually with relatively high trajectories; normally a cannon with a tube length of 20 to 30 calibers. 

  • A powerfully hit shot. 

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