ぐっすり（ぐっすり、guっsuri）
- soundly (sleep)

The Japanese word ぐっすり (gussuri) is an adverb that describes sleeping soundly or deeply. It signifies a state of complete and restful sleep, without any disturbance. It conveys the idea of a person sleeping very well and deeply, often implying a healthy and restorative sleep.

⚫︎赤ちゃんはぐっすり寝ています。 Translation: The baby is sleeping soundly. ⚫︎疲れていたので、ぐっすり眠れました。 Translation: Because I was tired, I was able to sleep soundly. ⚫︎昨夜はぐっすり眠って、気分が良くなりました。 Translation: I slept soundly last night and felt better.

ぐっすり is used to describe the state of sleep. ⚫︎ It is generally used when someone has slept well and without interruption. ⚫︎ It is often used to express relief that someone slept well, or to express admiration for someone’s peaceful sleep. ⚫︎ You would typically use ぐっすり to describe someone's sleep, not to describe the act of going to sleep. ⚫︎ It can be used in both formal and informal contexts.

⚫︎ ぐっすり is primarily written in hiragana. ⚫︎ It is not typically written in katakana or kanji. ⚫︎ There are no variations in okurigana.

There aren’t direct synonyms in Japanese, but here are some related words or phrases: ⚫︎ 熟睡 (じゅくすい) - deep sleep ⚫︎ 安眠 (あんみん) - sound sleep ⚫︎ 深く眠る (ふかくねむる) - to sleep deeply

There aren't many direct antonyms, but these might be considered opposites in meaning: ⚫︎ 眠れない (ねむれない) - cannot sleep ⚫︎ 寝不足 (ねぶそく) - lack of sleep ⚫︎ 浅い眠り (あさのねむり) - light sleep

試験の後、疲れてぐっすり眠りました。 ・Translation: After the exam, I was tired and slept soundly. ・Explanation: This sentence describes the speaker's state of deep sleep after being tired, indicating a good night's rest.

子供たちはぐっすり寝ているから、静かにしてください。 ・Translation: The children are sleeping soundly, so please be quiet. ・Explanation: This sentence is a request for silence because the children are sleeping deeply, indicating the importance of maintaining a peaceful environment.

The etymology of ぐっすり is uncertain, but it is considered to be a mimetic word (giongo) that imitates the sound or feeling of sleeping deeply. It's likely derived from the feeling or experience of sound sleep itself.