R

18th-century example of use of r rotunda in English blackletter typography

Letter ⟨R⟩ from the alphabet by Luca Pacioli, in De divina proportione (1509)

R is the eighteenth (number 18) letter in the English alphabet.

Meanings for R

On calendars, R is sometimes used as an short letter for Thursday instead of T, to avoid mistakes with Tuesday.
In chess, R is a notation symbol for the rook piece.
In geometry, R is most times a variable for the radius of a circle.
In navigation, R means the direction "right."
In movies, R means "restricted."
In Wheel of Fortune, R is one of the six letters given to any contestant participating in the "Bonus Round."

reconstruction of the Proto-Sinaitic resh glyph.
Phoenician letter res
Glyph shape found in ancient Greek epigraphy (Rho).
Half r (also round r, rotunda r); Unicode  (xF20E, Private Use Area) from the font en:Leeds Uni; created with en:Gimp. --- J. 'mach' wust • ˈkːlaːwːr̩ 12:08, 22 October 2005 (UTC)
reconstruction of the Proto-Sinaitic resh glyph.
PhoenicianR
One epigraphic letter shape of ancient Greek letter Rho.
Etruscan R variant
Latin capital letter R in the style of the Roman Capitalis monumentalis, using the font Trajan Pro
The word prognatuscode: la is deprecated as written on the Sarcophagus of Lucius Cornelius Scipio Barbatus (280 BC) reveals the full development of the Latin ⟨R⟩ by that time; the letter ⟨P⟩ at the same time still retains its archaic shape distinguishing it from Greek or Old Italic rho.
Alveolartrill
An alveolar approximant: [ɹa aɹa].
Alveolartap
Pronunciation of a voiced retroflex fricative, [ʐ] between two [a]s; [ʐa aʐa] by 44-year-old cis male speaker raised in Stockholm and Moscow.
Pronunciation of a retroflex approximant, [ɻ]: [ɻa aɻa].
Retroflexflap
Uvulartrill
Voiceduvularfricative