infestive

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 laborious mean murder oppressive pesky pestiferous pestilential refractory repressive rough tiresome troublous trying ungovernable uphill upsetting vexatious wearisome wicked

agreeable aiding beneficial delicate easy gentle helpful kind manageable nice pleasant pleasing safe uncomplicated

useful