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

/ spĭ-sĭf′ĭk /

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

Example Sentences

Their specific gravity allows them to sink and walk or run along the bottom of rivers and lakes.

From Salon

Galileo also wanted to construct an object which would fully immerse but not sink—an object with the same specific gravity as water.

From Literature

The study also found that, at fight-time, 39% of the fighters were either significantly or seriously dehydrated as measured by urine specific gravity.

From Salon

It was part of his job to dip a bottle on a rope, known as a thief, into the tanks to collect a sample so the oil’s consistency, or specific gravity, could be ascertained.

From Seattle Times

Here, Russian missiles had a distinct advantage, as their lower specific gravity allowed them to float vertically, like an ocean buoy.

From Washington Post