head of hair vs sidelock

head of hair

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

sidelock

noun
  • A lock of hair worn at the side of the head. 

  • The design of a gun that has the lockwork mounted to the inside of a plate; compare boxlock. 

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