Taru adjective, Adverb taking the 'to' particle
magnificent; grand; impressive; dignified; majestic; imposing; stately
その老人は堂々とした顔つきをしていた。The old man had a noble countenance. fair; square; open; unashamed; brazen
Adverb taking the 'to' particle
grandly; boldly; confidently
fairly; squarely; unreservedly; brazenly
Also written 堂堂【どうどう】