A quick or short temper; a tendency to get irritated or lose patience easily.
彼は短気だから、注意されるとすぐに怒る。
He's short-tempered, so he gets angry as soon as he's scolded.
短気を起こして後で後悔することが多い。
He often regrets losing his temper afterwards.
短気な人とは慎重に話したほうがいい。
It's better to speak carefully with short-tempered people.