Definition of

R

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

via WordNet, Princeton University

Synonyms of R

Hyponyms: radius of curvature, semidiameter

Hypernyms: alphabetic character, constant, length, letter, letter of the alphabet, radioactivity unit

In a circle, meaning "registered (trademark)," first incorporated in U.S. statues 1946. Three Rs (1825) said to have been given as a toast by Sir W. Curtis (1752-1829). R&R "rest and relaxation," first recorded 1953, Amer.Eng.; R&B "rhythm and blues" (type of popular music) first attested 1949, Amer.Eng.

r_almeid Vigília da renovação com @prandresouza foi ÓTIMA. Dúvida cruel: cama ou Mecânica I? rsrs
The_R_sisters No oir una pregunta y arriesgarte a que la respuesta que tu das sea la correcta #tension
R_alflchawe بـعـض البــشـر مايصـــــغره غــــير كـــلامـه .. وبعـــض البـــشر كـــلامه يجـــبرك عــلى احتــــرامه .."
shizzmac27 @pebdalioness yea once I see her again r get her # it's over lol