Fair, open, and dignified; acting openly and without cheating—used for conduct like competing fairly or speaking boldly but honestly.
彼は不正をせず、正々堂々と勝負した。
He didn't cheat and competed fair and square.
選挙では正々堂々と自分の政策を訴えるべきだ。
In elections you should advocate your policies openly and honestly.
問題があるなら、正々堂々と証拠を示して話し合おう。
If there's a problem, let's discuss it openly by showing the evidence.