the fact of being hard but easily broken 坚硬但容易破碎的事实 the hardness and brittleness of coal 煤的硬度和脆性
the fact of appearing to be strong but actually being easily damaged 脆性: 看起来很坚固但实际上很容易损坏the growing brittleness of the country's economy 该国经济日益脆弱
the fact of appearing to be happy or confident but actually being nervous and easily upset 脆性: 看起来很快乐或自信,但实际上却很紧张,容易沮丧There was some brittleness in his tone. 他的语气有些脆弱。