co-wife vs mot

co-wife

noun
  • In a polygamous marriage, another wife of a woman’s husband. 

mot

noun
  • A woman; a wife. 

  • A witty remark; a witticism; a bon mot. 

  • A prostitute. 

  • A landlady. 

How often have the words co-wife and mot occurred in a corpus of books? (source: Google Ngram Viewer )