blunder vs thrash about

blunder

verb
  • To move blindly or clumsily. 

  • To make a clumsy or stupid mistake. 

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

  • To cause to make a mistake. 

noun
  • A clumsy or embarrassing mistake. 

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

thrash about

verb
  • to move unpredictably and often violently, usually unaware 

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