blunder vs overestimate

blunder

verb
  • To make a clumsy or stupid mistake. 

  • To do or treat in a blundering manner; to confuse. 

  • To move blindly or clumsily. 

  • To cause to make a mistake. 

noun
  • A clumsy or embarrassing mistake. 

  • A very bad move, usually caused by some tactical oversight. 

overestimate

verb
  • To judge or calculate too highly. 

noun
  • An estimate that is too high. 

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