above-board vs unobtrusive

above-board

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

adv
  • Honestly; openly. 

unobtrusive

adj
  • Not obtrusive; not blatant or noticeable; discreet, inconspicuous. 

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