adverb, adverb taking the 'to' particle
sleeping peacefully; soundly; quietly
Describes a calm, comfortable sleeping state, often of babies or children. Mimetic word evoking gentle, rhythmic breathing.
赤ちゃんがすやすや眠っている。
The baby is sleeping peacefully.
疲れていたのか、彼はすやすやと寝息を立てていた。
Perhaps he was tired; he was breathing quietly in his sleep.
The baby is sleeping peacefully.
The child is fast asleep, breathing calmly.