adverb taking the 'to' particle, taru-adjective
towering; outstandingly great
Archaic literary word describing mountains towering imposingly or a person of exceptional greatness. Used with と or in たる form.
その山は巍然としてそびえ立っていた。
The mountain rose toweringly.
彼は巍然たる人物として尊敬された。
He was respected as a person of outstanding greatness.