くっと

くっと, クッとkutto

adverb

  1. inadvertently (letting out a laugh)
  2. quickly
  3. all of a sudden
  4. all at once

Study it in Yanamino

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