append vs subjoin

append

verb
  • To add, as an accessory to the principal thing; to annex 

  • To write more data to the end of a pre-existing file, string, or other object. 

  • To hang or attach to, as by a string, so that the thing is suspended 

noun
  • An instance of writing more data to the end of an existing file. 

subjoin

verb
  • To add something to the end; to append or annex 

noun
  • A subordinate or secondary join. 

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