r | ||
1. | [ noun ] (physics) a unit of radiation exposure; the dose of ionizing radiation that will produce 1 electrostatic unit of electricity in 1 cc of dry air | |
Synonyms: | roentgen | |
Related terms: | radioactivity_unit | |
2. | [ noun ] the 18th letter of the Roman alphabet | |
Related terms: | letter Roman_alphabet | |
3. | [ noun ] (physics) the universal constant in the gas equation: pressure times volume = R times temperature; equal to 8.3143 joules per kelvin per mole | |
Synonyms: | universal_gas_constant gas_constant | |
Related terms: | constant physics | |
4. | [ noun ] (geometry) the length of a line segment between the center and circumference of a circle or sphere | |
Synonyms: | radius | |
Related terms: | length radius_of_curvature semidiameter diameter | |
Similar spelling: |
Rh Ru Re Ro ri Ra Rae Rao Rau raw ray Rea Ree Rei Rew rye rho Ria Rio Roa roe row Roy rue rya Rey r-2 |