柯林斯词典specific gravity 1. N the ratio of the density of a substance to that of water 比重→see relative density 返回 specific gravity剑桥词典the mass of a particular volume of a substance when compared with the mass of an equal volume of water at 4°C. A more modern name for this is relative density . 比重，相对密度（现更常用 relative density） 返回 specific gravity