adverb taking the 'to' particle, adverb
choo-choo; chug-chug; hiss-hiss
Mimics the rhythmic puffing sound of a steam train or similar engine; often used with と.
The locomotive chugged away, puffing smoke.
adverb taking the 'to' particle, adverb
scrub-scrub; brush-brush
Represents the sound of scrubbing or brushing something briskly; also used with と.
My mother scrubbed the pot with a scourer, going 'scrub-scrub'.