飘渺 evokes something half-seen, half-imagined, distant peaks in cloud, fairy palaces, fading music, dreams. Common in classical poetry and contemporary fantasy/wuxia. Also written 缥缈 (same pronunciation, with 纟 silk radical), both forms are accepted.
memory
飘 (drift, float) + 渺 (vast and distant, note 氵 water radical, suggesting things lost in vastness). The image: something drifting at the edge of perception.