相对密度 xiāngduìmìdù relative density Definitions Defs Origin Strokes Stroke Words Sentences Sents 相对 相對 xiāngduì adverbadjective relative Existing or changing in relation to something else; relatively; comparatively; not absolute密度 mìdù density (physics) the ratio of the mass of a substance to its volume; formerly referred to as 比重 bǐzhòng