noun, adverb taking the 'to' particle
Onomatopoeic representation of a soft, restrained chuckle or giggle, often used by women or in lighthearted situations. Can function as a noun or adverbially with と.
See also: うふふ
彼女はウフッと笑った。
She chuckled softly.
その冗談に、彼はウフッと小さく笑った。
He let out a little chuckle at the joke.