pact vs understanding

pact

noun
  • An agreement; a compact; a covenant. 

  • An alliance or coalition. 

  • An agreement between two or more nations 

verb
  • To form a pact; to agree formally. 

understanding

noun
  • An informal contract; mutual agreement. 

  • Opinion, judgement or outlook. 

  • A reconciliation of differences. 

  • The act of one that understands or comprehends; comprehension; knowledge; discernment. 

  • Sympathy. 

  • Reason or intelligence, ability to grasp the full meaning of knowledge, ability to infer. 

adj
  • Showing compassion, tolerance, and forbearance. 

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