expression, i-adjective
bad-tempered; aggressive; quarrelsome
Describes a person's disposition as rough, easily angered, or prone to conflict. Often used to characterize someone's personality or mood.
See also: 気の荒い
彼は気が荒いから、あまりからかわないほうがいい。
He has a bad temper, so you'd better not tease him too much.
あの選手は気が荒いことで有名だ。
That athlete is known for being aggressive.
The expression combines 気 (spirit, temper) with 荒い (rough, wild). The exact historical derivation is uncertain, but it follows a common pattern of describing temperament with 気が + adjective.