at a brunt

not-comparable obsolete

(obsolete) suddenly and violently, all at once

Japanese Meaning

一気に、突然かつ暴力的に起こる様子 / 一斉に急激に物事が起こる状態

The cavalry charged at a brunt, scattering the enemy lines in an instant.

騎兵隊は突如として激しく突撃し、一瞬で敵の陣形を散らした。

Sense（1）

(obsolete) suddenly and violently, all at once