The 18th letter of the English alphabet, a consonant any spoken sound represented by the letter R or r, as in ran, carrot, or rhyme something having the shape of R a written or printed representation of the letter R or r a device, as a printer's type, for reproducing the letter R or r three R4 minutes to read;R 1 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 Introduction To R And Rstudio Reddit