adverb, adverb taking the 'to' particle
laughing loudly; with a hearty laugh
Mimetic adverb describing a loud, open laugh. Often used with 笑う or と.
彼は呵呵と笑った。
He laughed loudly.
その冗談を聞いて、みんなが呵呵大笑した。
Hearing the joke, everyone burst into loud laughter.
Mimetic word derived from the sound of loud laughter. The kanji 呵 is used phonetically for its on-reading カ, and the repetition suggests continuous or emphatic laughing.