decidedly vs incredibly

decidedly

adv
  • In a manner which leaves little question; definitely, clearly. 

  • In a decided or final manner; resolutely. 

incredibly

adv
  • To a great extent; extremely. 

  • In an incredible manner; not to be believed. 

  • Used to note the surprising or hard-to-believe nature of what is being said and suggest that it is nevertheless true. 

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