C1a fault, mistake, or weakness, especially one that happens while something is being planned or made, or that causes something not to be perfect错误;缺点;缺陷,瑕疵
I returned the material because it had a flaw in it.我退掉了那块布料,因为有瑕疵。
There's a fatal flaw in your reasoning.你的推理有一处致命的缺陷。