African-American vs tar baby

African-American

noun
  • A black American. 

  • Any black person. 

adj
  • Of or pertaining to the culture of African-American people. 

  • An American who is of Sub-Saharan African ancestry. 

  • American and black. 

  • Of Black African descent. 

tar baby

noun
  • A black person. 

  • A difficult, abstract problem that worsens as one attempts to handle it; a "sticky" situation, especially one where attempts to make it better only make it worse. 

How often have the words African-American and tar baby occurred in a corpus of books? (source: Google Ngram Viewer )