柯林斯詞典silica /?s?l?k?/ 1. N-UNCOUNT Silica is silicon dioxide, a compound of silicon which is found in sand, quartz, and flint, and which is used to make glass. 二氧化矽 返回 silica劍橋詞典a mineral that exists in various forms , including sand , quartz , and flint , used to make glass and cement 矽石，二氧化矽 返回 silica