adverb
Describes an action that happens or changes abruptly, instantly, or with a burst of speed. Often used with verbs like 光る, 走る, 立ち上がる.
部屋の電気がぱっとついた。
The room lights suddenly came on.
彼はぱっと立ち上がって外に出た。
He quickly stood up and went outside.
adverb, noun or participle which takes 'suru'
conspicuously; strikingly; showily
Used for something that stands out visually or makes a strong impression, often in a positive or flashy way. Common in the negative form ぱっとしない (unremarkable, dull).
See also: ぱっとしない
彼女はぱっとした服装でパーティーに現れた。
She showed up at the party in a flashy outfit.
今日の試合はぱっとしなかった。
Today's game was unremarkable.