ichidan verb, intransitive verb
snap; lose one's temper; flip out
Colloquial intransitive verb for suddenly becoming very angry or losing emotional control. Often used when someone's patience runs out.
See also: 切れる (きれる)
彼は急にキレて、机を叩いた。
He suddenly snapped and hit the desk.
That teacher loses his temper easily, so be careful.