noun, often capitalized, often attributive
\ ˈär How to pronounce r (audio) \
plural r's or rs\ ˈärz How to pronounce rs (audio) \

Definition of r

 (Entry 1 of 4)

1a : the 18th letter of the English alphabet
b : a graphic representation of this letter
c : a speech counterpart of orthographic r
2 : a graphic device for reproducing the letter r
3 : one designated r especially as the 18th in order or class
4 : something shaped like the letter R

Definition of r (Entry 2 of 4)

1 radius
2 rain
3 range
4 rare
5 real
6 recto
7 red
8 repeat
9 rerun
10 resistance
11 right
12 roentgen
13 rook
14 rough
15 run

Definition of R (Entry 3 of 4)

1 rabbi
2 radial
3 radical used especially of a monovalent hydrocarbon radical
4 Rankine
5 Reaumur
6 recipe
7 registered trademark often enclosed in a circle
8 regular
9 Republican
10 river
11 R-value

Definition of R (Entry 4 of 4)

used to certify that a motion picture is of such a nature that admission is restricted to persons over a specified age (such as 17) unless accompanied by a parent or guardian — compare g, nc-17, pg, pg-13

Examples of r in a Sentence

Noun There are two r's in “tomorrow.” “River” begins and ends with r.

First Known Use of r


before the 12th century, in the meaning defined at sense 1a

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Time Traveler for r

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The first known use of r was before the 12th century

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Cite this Entry

“R.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/r. Accessed 7 Jun. 2020.

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More Definitions for r

How to pronounce R (audio)

English Language Learners Definition of r

: the 18th letter of the English alphabet


noun, often capitalized
\ ˈär How to pronounce r (audio) \
plural r's or rs\ ˈärz \

Kids Definition of r

: the 18th letter of the English alphabet

Kids Definition of r.


Kids Definition of R


Kids Definition of R.


Medical Definition of r

 (Entry 1 of 3)


Medical Definition of R (Entry 2 of 3)

1 Reaumur
2 rough used in bacteriology

Medical Definition of R (Entry 3 of 3)

chemical group and especially an organic chemical group thiols have the general formula RSH

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More from Merriam-Webster on r

Spanish Central: Translation of r

Nglish: Translation of r for Spanish Speakers

Britannica.com: Encyclopedia article about r

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