/ahr/ , n. , pl. 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. See three R's .