correspondence vs synonym

correspondence

noun
  • A relation. 

  • Reciprocal exchange of civilities, especially conversation between persons by means of letters. 

  • Postal or other written communications. 

  • An agreement of situations or objects with an expected outcome. 

  • Newspaper or news stories. 

  • A similarity between physical and spiritual things (e.g. light to wisdom, or warmth to love) 

synonym

noun
  • A word whose meaning is the same as that of another word. 

  • An alternative (often shorter) name defined for an object in a database. 

  • Any name for a taxon, usually a validly published, formally accepted one, but often also an unpublished name. 

  • A word or phrase with a meaning that is the same as, or very similar to, another word or phrase. 

  • Any of the formal names for a taxon, including the valid name (i.e. the senior synonym). 

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