inopportune vs unappropriate

inopportune

adj
  • Unsuitable for some particular purpose. 

  • Happening/occurring at an inconvenient or inappropriate time. 

unappropriate

adj
  • Inappropriate; unsuitable. 

verb
  • To take from private possession; to restore to the possession or right of all. 

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