biracial vs multiracial

biracial

noun
  • A person belonging to two races. 

adj
  • Of or pertaining to two races 

  • Having parents of two races 

multiracial

noun
  • An individual of more than one race. 

adj
  • Composed of, or having a mixture of, multiple races. 

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