Random Linguistics Definitions Beginning with the Letter "R"

rhotic A term used in English phonology referring to dialects or accents where /r/ is pronounced following a vowel, as in car and cart. Varieties which do not have this feature are non-rhotic (such as received pronunciation). Vowels which occur after retroflex consonants are sometimes called rhotacized (they display rhotacization).

right dislocation In grammatical description, a type of sentence in which one of the constituents appears in final position and its canonical position is filled by a pronoun with the same reference, e.g. I know her, Julie; He's always late, that chap.

rim The edges of the tongue, the extent of whose contact with the roof of the mouth can affect the quality of several sounds, such as [s] and [l].

Definitions from: A Dictionary of Linguistics and Phonetics, Sixth edition, 2008
Image credits: Wikipedia - Flag semaphore representation of letter 'R'