plural of small "r" republican (alternative spelling of small-r republicans).

(phonology) A vowel modified so that the frequency of its third formant is lowered.

(astronomy) Abbreviation of Hertzsprung-Russell diagram.

(music) A genre of modern popular hip hop dance music influenced by funk and pop music.

(ASoIaF/GOT fandom slang) In A Song of Ice and Fire and Game of Thrones, the theory that the character Jon Snow is the child of Rhaegar Targaryen and Lyanna Stark. In Games of Thrones, this theory was shown to be correct.

plural of aged R-value

Abbreviation of Hertzsprung-Russell diagrams; plural of H-R diagram.

plural of R-coloured vowel

(psychology) The 1987 revision of the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association.

To make an alveolar trill sound for the letter r.