gas constant

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A constant, equal to 8.314 joules per kelvin, 0.08206 liter atmospheres per mole kelvin, or 1.985 calories per degree Celsius, that is the constant of proportionality in the ideal gas law.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun physics a universal constant, R, that appears in the ideal gas law, (PV = nRT), derived from two fundamental constants, the Boltzman constant and Avogadro's number, (R = NAk)

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (physics) the universal constant in the gas equation: pressure times volume = R times temperature; equal to 8.3143 joules per kelvin per mole