surrogate

Adjective

• providing or receiving nurture or parental care though not related by blood or legal ties
  • foster parent
    
  • foster child
    
  • foster home
    
  • surrogate father
    

Noun

• a person appointed to represent or act on behalf of others

• someone who takes the place of another person

Related words

• Synonyms: 
  foster , deputy , alternate , replacement