head of hair vs merkin

head of hair

noun
  • All the hair that covers the scalp of a person (excludes the beard and moustache) 

merkin

noun
  • The male counterpart of a beard, a companion to a lesbian to feign her straightness. 

  • An American. 

  • A mop for cleaning cannon. 

  • A woman's pubic wig. Worn for nude stage appearances and by women, originally after shaving their pubic hair to eliminate lice or for other reasons, now often as a fashion item. 

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