taru-adjective, adverb taking the 'to' particle
proper; correct; neat; upright
Formal or literary term describing a person's appearance, posture, or demeanor as proper, upright, and neat. Often used with と (端然と) to modify verbs.
彼は端然と座っていた。
He sat upright and proper.
端然とした態度で答える。
Answer with a correct and neat attitude.