Droop : bend or hang downwards limply. Strike : hit forcibly and deliberately with one's hand or a weapon or other implement. Challenge : a call to someone to participate in a competitive situation or fight to decide who is superior in terms of ability or strength. Warn : inform someone in advance of a possible danger, problem, or other unpleasant situation. Wilt : (of a plant, leaf, or flower) become limp through heat, loss of water, or disease; droop.