R

¹

or r

[ ahr ]

noun

, plural R's or Rs, r's or rs.

1. the 18th letter of the English alphabet, a consonant.
2. any spoken sound represented by the letter R or r, as in ran, carrot, or rhyme.
3. something having the shape of R .
4. a written or printed representation of the letter R or r.
5. a device, as a printer's type, for reproducing the letter R or r.
6. three R's.

R.

²

or R.

abbreviation for

1. (in prescriptions) take.

R

³

[ ahr ]

verb

1. Informal. are:

   Oysters R in season.

R.

⁴

abbreviation for

1. rabbi.
2. Radical.
3. radius.
4. railroad.
5. railway.
6. (in South Africa) rand; rands.
7. Réaumur.
8. rector.
9. redactor.
10. regina.
11. Republican.
12. response.
13. rex.
14. river.
15. road.
16. royal.
17. ruble.
18. rupee.
19. Theater. stage right.

R

⁵

abbreviation for

1. Trademark. restricted: a rating assigned to a movie by the MPA indicating that children under the age of 17 will not be admitted to a theater showing the film unless accompanied by an adult. Compare G ³( def ), NC-17, PG ¹, PG-13.

R

⁶

abbreviation for

1. Chemistry. radical.
2. Mathematics. ratio.
3. regular: a man's suit or coat size.
4. Electricity. resistance.
5. Theater. stage right.
6. Physics. roentgen.
7. Chess. rook.

R

⁷

Symbol.

1. the 18th in order or in a series.
2. (sometimes lowercase) the medieval Roman numeral for 80. Compare Roman numerals.
3. Biochemistry. arginine ( def ).
4. Physics. universal gas constant.
5. registered trademark: written as superscript ® following a name registered with the U.S. Patent and Trademark Office.

r

⁸

Ecology.

1. the theoretical 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.

r

⁹

abbreviation for

, plural rs,

1. radius.
2. Commerce. registered ( def 2 ).
3. Electricity. resistance.
4. Physics. roentgen ( def 2 ).
5. royal.
6. ruble.
7. plural rs rupee.

r.

¹⁰

abbreviation for

, plural rs.

1. rabbi.
2. railroad.
3. railway.
4. range.
5. rare.
6. Commerce. received.
7. recipe.
8. replacing.
9. residence.
10. right.
11. rises.
12. river.
13. road.
14. rod.
15. royal.
16. rubber.
17. ruble.
18. Baseball. run; runs.
19. plural rs rupee.

R.

¹

abbreviation for

1. registered (trademark)
2. right
3. river
4. rouble

R.

²

abbreviation for

1. rabbi
2. rector
3. Regina
4. Republican
5. response (in Christian liturgy)
6. Rex
7. River
8. Royal

r.

³

abbreviation for

1. rare
2. recto
3. Alsor rod (unit of length)
4. ruled
5. cricket baseball run(s)

R

⁴

symbol for

1. chem radical
2. currency
   1. rand
   2. rupee
3. Réaumur temperature (scale)
4. physics electronics resistance
5. roentgen or röntgen
6. chess rook
7. Royal
8. chem gas constant
9. in the US and Australia
   1. restricted exhibition (used to describe a category of film certified as unsuitable for viewing by anyone under the age of 18)
   2. ( as modifier )

      an R film

r

⁵

/ ɑː /

noun

1. the 18th letter and 14th consonant of the modern English alphabet
2. a speech sound represented by this letter, in English usually an alveolar semivowel, as in red
3. See three Rs

r

1. Abbreviation of radius

Word History and Origins

Origin of R¹

From the Latin word recipe

Origin of R²

An American designation established in 1968

Word History and Origins

Origin of R¹

(sense 3) Latin: Queen

Idioms and Phrases

see three R's .