# r

R

– definition :

• (noun)
1. the length of a line segment between the center and circumference of a circle or sphere (context:attribute)
2. the 18th letter of the Roman alphabet (context:communication)
3. (physics) the universal constant in the gas equation: pressure times volume = R times temperature; equal to 8.3143 joules per kelvin per mole (context:quantity)
4. a unit of radiation exposure; the dose of ionizing radiation that will produce 1 electrostatic unit of electricity in 1 cc of dry air (context:quantity)

r