ドキッと

adverb, noun or participle which takes 'suru'

with a start; with a shock; startled

Describes a sudden, brief feeling of surprise or fright, often accompanied by a physical jolt. Commonly used with する to mean 'to be startled' or 'to get a shock'.

• 突とつ然ぜんの大おおきな音おとにドキッとした。

  I was startled by the sudden loud noise.