inappropriate vs undue

inappropriate

adj
  • Not appropriate; not suitable for the situation, time, or place. 

  • Improper; adult; sexual. 

undue

adj
  • Not owing or payable. 

  • That which ought not to be done; illegal; unjustified. 

  • Excessive; going beyond that what is natural or sufficient. 

How often have the words inappropriate and undue occurred in a corpus of books? (source: Google Ngram Viewer )