loony vs round the bend

loony

noun

  • An insane or very foolish person. 

adj

  • Insane. 

  • Very silly, absurd. 

round the bend

prep

  • Crazy, mad or insane. 

  • Close to or in close proximity to another location. 

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