about-face vs severing

about-face

verb

  • To turn 180 degrees to face the opposite direction. 

  • To change opinion or attitude drastically. 

noun

  • A reversal in direction; a reversal of attitude or opinion. 

  • An abrupt turn to face the opposite direction. 

severing

noun

  • The act by which something is severed. 

How often have the words about-face and severing occurred in a corpus of books? (source: Google Ngram Viewer )