taru-adjective, adverb taking the 'to' particle
self-possessed; calm and composed
Literary or formal word describing a person's dignified, unhurried composure. Often used in the adverbial form 悠揚と.
He remains calm and composed no matter what.
He answered the questions with a self-possessed demeanor.
The exact derivation is uncertain; the kanji 悠 (distant, leisurely) and 揚 (raise, elevate) together suggest a lifted, unhurried state of mind.