R(redirected from Sound Reduction Index)
Also found in: Thesaurus, Medical, Legal, Financial, Encyclopedia, Wikipedia.
A trademark for a movie rating indicating that admission will be granted only to persons of or over a certain age, usually 17, unless accompanied by a parent or guardian.
1. The symbol for gas constant.
2. The symbol for a hydrocarbon side chain or substituent of variable chemical structure.
1. range (surveying)
2. Réaumur (scale)
3. registered trademark
5. Ecclesiastical response
7. or r roentgen
8. rook (chess)
9. Baseball run
r 1or R (är)
n. pl. r's or R's also rs or Rs
1. The 18th letter of the modern English alphabet.
2. Any of the speech sounds represented by the letter r.
3. The 18th in a series.
4. Something shaped like the letter R.
1. Mathematics radius
2. Genetics recombinant
3. or R Electricity resistance
n, pl r's, R's or Rs
1. (Linguistics) the 18th letter and 14th consonant of the modern English alphabet
2. (Phonetics & Phonology) a speech sound represented by this letter, in English usually an alveolar semivowel, as in red
3. (Education) See three Rs
1. (Chemistry) chem radical
2. (Currencies) currency
3. (General Physics) Réaumur temperature (scale)
4. (General Physics) physics electronics resistance
5. (General Physics) roentgen or röntgen
6. (Chess & Draughts) chess rook
8. (Chemistry) chem gas constant
9. (Film) (in the US and Australia)
a. restricted exhibition (used to describe a category of film certified as unsuitable for viewing by anyone under the age of 18)
b. (as modifier): an R film.
n., pl. Rs R's, rs r's.
1. the 18th letter of the English alphabet, a consonant.
2. any spoken sound represented by this letter.
3. something shaped like an R.
4. a written or printed representation of the letter R or r.
1. Chem. radical.
2. Math. ratio.
3. regular: a man's suit or coat size.
4. restricted: a motion-picture rating advising that children under 17 will not be admitted unless accompanied by an adult. Compare G (def. 2), NC-17, PG, PG-13, X (def. 7).
1. the 18th in order or in a series.
3. registered trademark: written as superscript ® following a name registered with the U.S. Patent and Trademark Office.
4. Elect. resistance.
2. Elect. resistance.
pl. rs, rupee.
pl. rs, rupee.
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. Also called Malthusian parameter.
6. (in South Africa) rand.
8. Also, R (in prescriptions) take.
[< Latin recipe]
12. Eccles. response.
6. Com. received.
16. Baseball. run.
pl. rs. rupee.
pl. rs. rupee.
1. Mathematics Abbreviation of radius
2. or R Electricity Abbreviation of resistance
Switch to new thesaurus
|Noun||1.||R - a unit of radiation exposure; the dose of ionizing radiation that will produce 1 electrostatic unit of electricity in 1 cc of dry air|
radioactivity unit - a measure of radioactivity
|2.||R - (physics) the universal constant in the gas equation: pressure times volume = R times temperature; equal to 8.3143 joules per kelvin per mole|
natural philosophy, physics - the science of matter and energy and their interactions; "his favorite subject was physics"
constant - a number representing a quantity assumed to have a fixed value in a specified mathematical context; "the velocity of light is a constant"
|3.||r - the 18th letter of the Roman alphabet|
Latin alphabet, Roman alphabet - the alphabet evolved by the ancient Romans which serves for writing most of the languages of western Europe
|4.||r - the length of a line segment between the center and circumference of a circle or sphere|
diam, diameter - the length of a straight line passing through the center of a circle and connecting two points on the circumference
semidiameter - the apparent radius of a celestial body when viewed as a disc from the earth
radius of curvature - the radius of the circle of curvature; the absolute value of the reciprocal of the curvature of a curve at a given point
length - the linear extent in space from one end to the other; the longest dimension of something that is fixed in place; "the length of the table was 5 feet"
R1 r1 [ɑːʳ] N (= letter) → R, r f
R for Robert → R de Ramón
the three Rs (= reading, writing and arithmetic) lectura, escritura y aritmética THREE RS
1. (Brit) =Rex → R
2. (Brit) =Regina → R
3. (Geog) =river → R
4. =right → dcha, der, dero
5. =Réaumur (scale)
6. (US) (Pol) =Republican