call off vs countermand

call off

verb
  • To recall; to cancel or call a halt to. 

  • To telephone in one's notice of a day's absence from work. 

countermand

verb
  • To cancel an order for (some specified goods). 

  • To recall a person or unit with such an order. 

  • To counteract, to act against, to frustrate. 

  • To revoke (a former command); to cancel or rescind by giving an order contrary to one previously given. 

noun
  • An order to the contrary of a previous one. 

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