(phonetics, phonology, informal) a rhotic sound which is emphatic or strongly enunciated; in English accents especially a postvocalic consonantal r, as distinguished from its absence in a nonrhotic accent or from an R-coloured vowel

plural of hard r

(US, film) a movie that is definitely, or most likely will be, R-rated ("Under 17 requires accompanying parent or adult guardian.") by the Motion Picture Association (MPA), typically due to having multiple scenes of violence or nudity.