caretaker vs co-parent

caretaker

noun
  • Someone who takes care of a person; a parent, carer or other guardian. 

  • Someone who takes care of a place or thing; someone looking after a place, or responsible for keeping it in good repair. 

adj
  • Temporary, on a short term basis. 

co-parent

noun
  • Someone who shares in the parenting of a child or children, such as 

  • A godparent. 

  • A divorced or separated parent who shares custody with the other parent. 

  • A parent in a same-sex couple. 

verb
  • To act as a co-parent; to share custody of a child or children; to share in the responsibility of parenting a child or children. 

How often have the words caretaker and co-parent occurred in a corpus of books? (source: Google Ngram Viewer )