1. magnificent; grand; impressive; dignified; majestic; imposing; stately
その堂々たる姿が少女には驚きだった。The girl was surprised by its majestic appearance.
2. fair; square; open; unashamed; brazen
3. grandly; boldly; confidently
一人でも堂々とできるのって、すごいよ。It's amazing that you can do it confidently even on your own.
4. fairly; squarely; unreservedly; brazenly
教室で堂々とそう呼ぶのやめてくれないか？Could you stop calling me that so openly in the classroom?