specific gravity

[spi-sif-ik grav-i-tee]

noun

Physics.

1. the ratio of the density of any substance to the density of some other substance taken as standard, water being the standard for liquids and solids, and hydrogen or air being the standard for gases.

specific gravity

noun

1. the ratio of the density of a substance to that of water See relative density

specific gravity

1. The relative density of a solid or liquid, usually when measured at a temperature of 20°C, compared with the maximum density of water (at 4°C). For example, the specific gravity of carbon steel is 7.8, that of lead is 11.34, and that of pure gold is 19.32.

specific gravity

1. The mass of a substance, given as a multiple of the mass of the same volume of a standard substance (usually water). The specific gravity of aluminum is 2.70; hence, a cubic foot of aluminum weighs 2.70 times as much as a cubic foot of water.

Word History and Origins

Origin of specific gravity¹

First recorded in 1660–70; the variant relative density was first recorded in 1875–80