brother-in-law vs maternal cousin

brother-in-law

noun
  • The brother of the spouse of one's sibling. 

  • The brother of one's spouse. 

  • The husband of the sibling of one's spouse. 

  • The husband of one's sibling. 

maternal cousin

noun
  • A child of one's mother's sibling 

  • A more distant relative of one's mother who is not a direct ancestor 

How often have the words brother-in-law and maternal cousin occurred in a corpus of books? (source: Google Ngram Viewer )