barking mad vs hatstand

barking mad

adj
  • Completely insane. 

hatstand

adj
  • Crazy, insane. 

noun
  • A device used to store hats upon, consisting of a vertical pole with a sturdy base to prevent toppling, and an array of pegs to hold the hats. 

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