An onomatopoeic adverb describing a peaceful, sound, or sleep—often used for babies or small animals sleeping gently.
赤ちゃんがすやすやと眠っている。
The baby is sleeping peacefully.
ソファで猫がすやすや丸くなっていた。
A cat was curled up on the sofa, sleeping soundly.
彼は疲れていて、ベッドに入ったらすやすやと眠りに落ちた。
He was tired and fell asleep peacefully as soon as he got into bed.