silent; quiet 安静的,无声的 the cycle is a benign form of transport, being noiseless and non-polluting. 自行车是一种无害的交通工具,既安静又无污染。 given to almost noiseless fits of giggling. 喜欢发出一阵阵几乎无声的笑。 ■(technical)accompanied by or introducing no random fluctuations that would obscure the real signal or data (技)无杂音的,无噪声的