head over heels vs lose one's head

head over heels

adv
  • Hopelessly, madly, to distraction, deeply, utterly. 

  • At top speed; frantically. 

  • Tumbling upside down; somersaulting. 

adj
  • Hopelessly smitten, madly in love. 

lose one's head

verb
  • To suffer decapitation. 

  • To be killed, usually in a gruesome manner. 

  • To be dismissed from a job. 

  • To behave irrationally or to lose one's self-control, especially in a distressing situation or as a result of falling in love. 

How often have the words head over heels and lose one's head occurred in a corpus of books? (source: Google Ngram Viewer )