Antonyms for "be quiescent" include words such as "agitate", "disturb", "roil", "stir up", and "excite". These words suggest a state of restlessness, movement, or chaos. "Agitate" implies causing a sense of unease or disturbance, while "disturb" suggests interrupting a state of calm or tranquility. "Roil" and "stir up" depict a state of turbulent motion, while "excite" signifies a feeling of enthusiasm or heightened emotions. Using antonyms for "be quiescent" can help to convey a sense of action, motion, or energy, often in contrast to a peaceful or inactive state.