カッとなる

かっとなる
expression
to lose one's temper, to flare up, to get hot-headed
1. to lose one's temper, to flare up suddenly
To suddenly become angry and lose control of one's emotions. The mimetic カッと represents the sudden flash of anger.
カッとなって怒鳴(どな)った。
I lost my temper and yelled.
カッとなりやすい性格(せいかく)だ。
I have a short temper.
カッとなって(なぐ)ってしまった。
I got so angry I ended up hitting them.
カッとならないで冷静(れいせい)(はな)そう。
Don't lose your temper—let's talk calmly.

カッとなる uses the mimetic カッと to express the sudden, intense nature of the anger—like a flash of heat.

カッと by itself can describe:

  • Eyes opening wide suddenly (カッと()見開(みひら)く)
  • A sudden flash of heat or anger

Related expressions:

  • (あたま)()(のぼ)る (blood rushes to one's head)
  • ()れる (to snap, lose it - slang)
  • むかつく (to be pissed off)

Often used when explaining why someone did something regrettable in a moment of anger.