Specific gravity :  (noun)

1: the density of a substance relative to the density of water

G, G suit, apogeotropism, closeness, compactness, congestedness, congestion, consistence, consistency, crowdedness, denseness, density, firmness, geotropism, gluiness, gravitation, graviton, gravity, hardness, impenetrability, impermeability, imporosity, incompressibility, jammedness, mass, relative density, solidity, solidness, spissitude, thickness, viscidity, viscosity, viscousness,