alarming annoying burdensome damaging dangerous difficult inconvenient intractable irksome irritating messy painful problematic taxing tough tricky ugly unruly vexing worrying arduous demanding disquieting harassing hard heavy importunate infestive laborious mean murder oppressive pesky pestiferous pestilential refractory repressive rough tiresome troublous trying ungovernable uphill upsetting vexatious wearisome wicked