シュッシュッポッポ

シュッシュッポッポ, シュッシュッポッポッ, しゅっしゅっぽっぽ, しゅっしゅっぽっぽっshusshuppoppo

adverb

  1. chuff-chuff (sound of a steam engine)
  2. choo-choo
  3. chug-chug
  4. puff-puff

Study it in Yanamino

Data from JMdict, KANJIDIC2 (EDRDG), KanjiVG, CC-CEDICT and Make Me a Hanzi. Sources and licences