R (
http://definr.com/R)
n 1: a unit of radiation exposure; the dose of ionizing radiation
that will produce 1 electrostatic unit of electricity in
1 cc of dry air [syn:
roentgen,
R]
2: (physics) the universal constant in the gas equation:
pressure times volume = R times temperature; equal to
8.3143 joules per kelvin per mole [syn:
gas constant, {universal
gas constant},
R]
3: the 18th letter of the Roman alphabet [syn:
R]
4: the length of a line segment between the center and
circumference of a circle or sphere [syn:
radius]