ぎょっと

adverb, noun or participle which takes 'suru'

startled; taken aback

Mimetic word describing a sudden, sharp surprise or fright, often in reaction to something unexpected or shocking.

• 突とつ然ぜんの大おおきな音おとにぎょっとした。

  I was startled by the sudden loud noise.

• 彼かれの変かわりようにぎょっとした。

  I was taken aback by how much he had changed.