adverb, adverb taking the 'to' particle, noun or participle which takes 'suru'
trembling; shivering; shaking; quivering
Describes a continuous, rapid shaking of the body or a part of it, typically from cold, fear, anger, or excitement. Often used adverbially with と or as a する-verb.
寒くて体がぶるぶる震えた。
I was so cold my body trembled.
彼は怒りでぶるぶると拳を震わせた。
He shook his fist, trembling with anger.