adverb taking the 'to' particle, taru-adjective
smiling broadly; beaming
Literary adverb describing a broad, gentle smile. Used with と (e.g., 莞爾として) or in the form 莞爾たる. Rare in everyday speech; mainly found in written narratives.
彼は莞爾としてその場を去った。
He left the place with a broad smile.
莞爾たる笑みを浮かべて、彼女はうなずいた。
With a beaming smile, she nodded.