が荒い

is rough

→ が
phrase Rare #40,583
is rough Describes something as rough, harsh, or intense depending on the noun before が, such as driving, speech, breathing, or temperament.
JA: 彼は運転が荒い。
EN: He drives recklessly.

息が荒いが大切な話のようだな

You're breathing heavily, but this sounds important.

— イル・ポスティーノ (1994)

校長の気性が荒いという話は聞いていたが、実際に怒るところを見たことはなかった。

I’d heard the principal had a temper, but I’d never actually seen him get angry.

トムは運転が荒い。

Tom drives recklessly.