1Magnificent, grand, or dignified — having an impressive, stately presence or bearing.
彼は大会で堂々とスピーチをした。
He delivered a dignified speech at the competition.
古い図書館の建物は堂々とした佇まいだ。
The old library building has a grand, stately appearance.
彼女は堂々たる態度で面接に臨んだ。
She approached the interview with a confident, dignified manner.
2Fair, open, and unashamed — acting squarely, without dishonesty or anything to hide.
不正をせず堂々と勝負するべきだ。
You should compete fairly and squarely, without cheating.
彼は自分の過ちを堂々と認めた。
He openly admitted his mistake.
3Grandly, boldly, or confidently — acting with poise and self-assurance (adverbial use).
彼女は堂々と舞台に上がった。
She confidently walked up onto the stage.
問題を堂々と説明して、聴衆の信頼を得た。
He explained the issue confidently and won the audience's trust.
4Fairly, squarely, or brazenly — doing something openly and unreservedly, without hesitation (adverbial use).
彼は間違いを指摘されても堂々と反論した。
Even when his mistake was pointed out, he brazenly argued back.
費用は堂々と会社が負担する、と上司が宣言した。
The boss declared, without any hesitation, that the company would cover the costs.