reasonably vs unthinkably

reasonably

adv
  • Fairly; satisfactorily; not extremely. 

  • Quite; fairly; satisfactorily. 

  • In accordance with reason. 

unthinkably

adv
  • In an unthinkable manner. 

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