ぐっすり
ぐっすり · gussuri · JLPT N3 · adverb
sound asleep
🛏️ gussuri sounds like goose sorry: the goose is sorry, it was fast asleep
ぐっすり is a Japanese mimetic word for deep, unbroken sleep. The small っ adds a pause that makes it stronger. It often comes with 眠る or 寝る: ぐっすり眠る means to sleep soundly.