baby of the family vs boy

baby of the family

noun
  • The youngest member of an immediate family. 

  • A member of an immediate family who behaves as, or is treated as though they were the youngest member of a family. 

  • An adult member of an immediate family who is treated by others in the family, especially the parents, as though they were a child. 

boy

noun
  • A son of any age. 

  • A male of any age, particularly one rather younger than the speaker. 

  • A male servant, slave, assistant, or employee 

  • A younger such worker. 

  • A non-white male servant regardless of age, particularly as a form of address. 

  • Any non-white male, regardless of age. 

  • A male child or adolescent, as distinguished from infants or adults. 

  • A male (tree, gene, etc). 

  • A young male. 

  • A former low rank of various armed services; a holder of this rank. 

  • Heroin. 

  • A male animal, especially, in affectionate address, a male dog. 

verb
  • To act as a boy (in allusion to the former practice of boys acting women's parts on the stage). 

intj
  • Exclamation of surprise, pleasure or longing. 

How often have the words baby of the family and boy occurred in a corpus of books? (source: Google Ngram Viewer )