noun, noun or participle which takes 'suru'
quiet rest; lying down peacefully
Literary or formal term for resting quietly, often while lying down. Rare in everyday speech; 静養 (せいよう) or 安静 (あんせい) are more common modern equivalents.
病後はしばらく安臥が必要だ。
After the illness, a period of quiet rest is necessary.
彼は一日中安臥していた。
He lay resting quietly all day.