flabbergasted vs slack-jawed

flabbergasted

adj
  • Appalled, annoyed, exhausted or disgusted. 

  • Damned. 

slack-jawed

adj
  • With the mouth in an open position and the jaw hanging loosely, especially as indicating bewilderment or astonishment. 

  • Unsophisticated or unthinking; dimwitted in appearance. 

How often have the words flabbergasted and slack-jawed occurred in a corpus of books? (source: Google Ngram Viewer )