adverb, adverb taking the 'to' particle, noun or participle which takes 'suru'
glaringly; with a piercing stare
Describes staring intensely, often with a sharp or intimidating look. Commonly used with 見る or 睨む.
彼は私をぎろぎろ見た。
He stared at me glaringly.
知らない人がぎろぎろ
A stranger was glaring at me with a piercing look.