on the level vs truth-telling

on the level

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

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

truth-telling

adj
  • Telling the truth; honest, frank. 

noun
  • The act of telling the truth. 

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