on the level vs on the square

on the level

prep
  • Synonym of on the square (“discreet reference to freemasonry”) 

  • Honest(ly), sincere(ly), straightforward(ly), fair(ly). 

on the square

prep
  • A discreet, unassuming reference to freemasonry. 

  • Honest and open. 

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