brother-in-law vs full cousin

brother-in-law

noun

  • The husband of one's sibling. 

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

  • The brother of one's spouse. 

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

full cousin

noun

  • A first cousin. 

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