r

1 of 4

noun

ˈär

plural r's or rs ˈärz

often capitalized, often attributive

: the 18th letter of the English alphabet

: a graphic representation of this letter

: a speech counterpart of orthographic r

: a graphic device for reproducing the letter r

: one designated r especially as the 18th in order or class

: something shaped like the letter R

2 of 4

abbreviation (1)

radius

rain

range

rare

real

recto

red

repeat

rerun

resistance

right

roentgen

rook

rough

run

3 of 4

abbreviation (2)

rabbi

radial

radical

—used especially of a monovalent hydrocarbon radical

Rankine

Reaumur

recipe

registered trademark

—often enclosed in a circle

regular

Republican

river

R-value

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

Example Sentences

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

Word History

First Known Use

Noun

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

Time Traveler

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

See more words from the same century

Cite this Entry

Style

“R.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/r. Accessed 7 Dec. 2022.

Copy Citation

Kids Definition

1 of 2 noun

ˈär

often capitalized

: the 18th letter of the English alphabet

2 of 2 certification mark

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