Definitions for r
Random House Webster's College Dictionary
R, rɑr(n.)(pl.)Rs; R's, rs; r's.
the 18th letter of the English alphabet, a consonant.
any spoken sound represented by this letter.
something shaped like anR.
a written or printed representation of the letter R or
regular: a man's suit or coat size.
Category: Biochemistry, Clothing
restricted: a motion-picture rating advising that children under 17 will not be admitted unless accompanied by an adult.
Ref: Compare G (def. 2), 3 5 NC-17 , PG, 2 PG-13, 3 X (def. 7). 4 8
the 18th in order or in a series.
registered trademark: written as superscript ® following a name registered with the U.S. Patent and Trademark Office.
the intrinsic rate of increase of a population, equivalent to the difference between the birth and death rates divided by the number of individuals in the population.
Ref: Also called Malthusian parameter.
(in South Africa) rand.
Also, R (in prescriptions) take.
Origin of R.:
< L recipe
Category: Weights and Measures
a unit of radiation exposure; the dose of ionizing radiation that will produce 1 electrostatic unit of electricity in 1 cc of dry air
gas constant, universal gas constant, R(noun)
(physics) the universal constant in the gas equation: pressure times volume = R times temperature; equal to 8.3143 joules per kelvin per mole
the 18th letter of the Roman alphabet
the length of a line segment between the center and circumference of a circle or sphere
Kernerman English Learner's Dictionary
the 18th letter of the alphabet
r, the eighteenth letter of the English alphabet, is a vocal consonant. It is sometimes called a semivowel, and a liquid. See Guide to Pronunciation, // 178, 179, and 250-254
The Standard Electrical Dictionary
(a) Abbreviation and symbol for Reamur, as 10º R., meaning 10º by the Reamur thermometer. (See Reamur Scale.) (b) Symbol for resistance, as in the expression of Ohm's Law C=E. (rho, Greek r) Symbol for specific resistance.