mad as a mongoose vs weak-minded

mad as a mongoose

adj

  • Demented or crazy. 

weak-minded

adj

  • Foolish or ignorant. 

  • weak-willed; easily swayed or corrupted. 

  • mentally deficient 

  • Needy or fearful; characterized by weakness. 

How often have the words mad as a mongoose and weak-minded occurred in a corpus of books? (source: Google Ngram Viewer )