kusu-kusu
A quiet, stifled giggle — trying not to laugh out loud. The kind of laughter shared between friends during class.
💡Sharing a joke during a meeting — 'We were kusu-kusu the whole time.'
授業中にくすくす笑っていた。
We were kusu-kusu giggling during class.
The students were ___ at the teacher's funny mistake.
先生の面白い間違いに生徒たちが○○笑っていた。