aunt-in-law vs bahu

aunt-in-law

noun
  • The wife of one's uncle or aunt (parent's sibling). 

  • The aunt of one's husband. 

  • The aunt of one's wife. 

bahu

noun
  • A daughter-in-law or sister-in-law, especially one who lives with her husband's family when married. 

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