ピシャッと

adverb

with a slap; with a splat

Onomatopoeic adverb describing a sharp slapping or splatting sound, often used for hitting a surface or a wet impact.

• 彼かれは机つくえをピシャッと叩たたいた。

  He slapped the desk with a sharp sound.

• 雨あま粒つぶが窓まどにピシャッと当あたった。

  A raindrop splatted against the window.