relation vs rivalry

relation

noun
  • The manner in which two things may be associated. 

  • A set of ordered tuples. 

  • A set of ordered tuples retrievable by a relational database; a table. 

  • The act of intercourse. 

  • Specifically, a set of ordered pairs; a binary relation. 

  • The act of relating a story. 

  • A member of one's extended family; a relative. 

  • A statement of equality of two products of generators, used in the presentation of a group. 

  • A subobject of a product of objects. 

rivalry

noun
  • Any competition between two or more things or factors. 

  • The characteristic of being a rivalrous good, such that it can be consumed or used by only one person at a time. 

  • An ongoing relationship between (usually two) rivals who compete for superiority. 

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