Colloquial contraction of '腹が立つ'; to get angry or feel irritated.
そんな言い方をされて本当に腹立った。
I was really pissed off to be spoken to like that.
彼の約束を破った行動に腹が立つ。
I'm angry about his breaking his promise.
理不尽な扱いを受けて腹立つのをこらえた。
I held back my anger after being treated unfairly.
彼の無責任な発言にみんな腹立ったようだ。
It seems everyone got angry at his irresponsible comment.