append vs undo

append

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

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 

undo

verb
  • To reverse the effects of an action. 

  • To unfasten. 

  • To impoverish or ruin, as in reputation; to cause the downfall of. 

noun
  • An operation that reverses a previous action. 

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