piss 小便，off 有离开之意， piss sb off 语气比angry语气更严重，表示非常生气，惹人生气，使生气，使厌烦激怒某人，惹某人不快（不礼貌的说法）。

【例句】
He's mean! I asked him for help and he turned up his nose at me! It pissed me off!
他太刻薄了！我想让他帮个忙，结果他理都不理我！气死我了！

Her attitude really pisses me off.
她的态度让我厌烦极了。