oath vs pact

oath

noun
  • A statement or promise which is strengthened (affirmed) by such a pledge. 

  • A light, irreverent or insulting appeal to a deity or other entity. 

  • A curse, a curse word. 

  • A solemn pledge or promise that invokes a deity, a ruler, or another entity (not necessarily present) to attest the truth of a statement or sincerity of one's desire to fulfill a contract or promise. 

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. 

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