above-board vs honest to God

above-board

adv

  • Honestly; openly. 

adj

  • In open sight; without trick, concealment, or deception. 

honest to God

adv

  • Truly, really. 

  • Honest; truly, really; used to emphasize that a statement is true. 

How often have the words above-board and honest to God occurred in a corpus of books? (source: Google Ngram Viewer )