flaw, blemish

瑕 is composed of the radical 玉 (jade) and 叚 (borrow, false). 叚 is a pictograph of two hands grasping a cliff wall, meaning untrue or false. Thus, 瑕 refers to the untrue or imperfect parts of jade, originally meaning spots or blemishes on jade, later extending to faults or defects in general.