noun, noun or participle which takes 'suru'
deep sigh; long sigh
A heavy, prolonged sigh expressing deep emotion such as sorrow, regret, or relief. Often used in literary or formal contexts.
彼は深い悲しみの中で長嘆をついた。
He let out a deep sigh in his profound sorrow.
その知らせを聞いて、彼
Upon hearing the news, she heaved a long sigh.