interjection, adverb taking the 'to' particle
Mimetic word for a heavy, dull impact or thud, often used as an interjection or with と to describe a sudden heavy sound.
There was a loud thump.
He plopped down onto the sofa with a thud.
Hiragana spelling is also used.
Onomatopoeic word mimicking a heavy, dull impact sound. The exact origin is uncertain, but it is a conventional sound-symbolic form in Japanese.