adverb taking the 'to' particle
simmering; bubbling; welling up
Describes liquid simmering gently, or emotions/thoughts welling up inside. Often used with と (ふつふつと).
The water is simmering gently in the pot.
Anger welled up inside me.
Usually written in kana; the kanji forms 沸々 and 沸沸 are rare and mainly literary.
Rare kanji spelling; the repetition mark 々 is used, but the kana form is strongly preferred.
Rare kanji spelling without the repetition mark; even less common than 沸々.
An onomatopoeic word mimicking the sound and appearance of gentle boiling or bubbling. The kanji 沸 means 'boil' and is used for its meaning, but the word itself is native Japanese.