Rhotic

Rhotic (pronounced 'ROH-tick', with the 'OH' sound of 'go' - IPA: /ˈrəʊ tɪk/, is a term of phonetics. In the description of English, it labels those accents and dialects in which r is pronounced nearly everywhere it is written, such as Scots and South-west England, like Somerset. These r- pronouncing accents are distinguished from the non-rhotic, or non-r-pronouncing accents, notably RP and other accents of southern Britain, and most of the southern states of the USA, along with Boston and New York. Non-rhotic accents tend only to pronounce '-r-' when it comes before a vowel or between vowels. The rhotic accents pronounce it after a vowel as well, which the non-rhotic do not.

Speakers of RP, for example, never realise the '-r' at the end of words ending in '-er' or '-or'. "The driv-uh of a mot-uh cah" is a representation of how they - and a New Yorker - might pronounce 'the driver of a motor car'.

You may care also to see the article on the Intrusive '-r-'. There is also a word of the same origin, rhotacism, meaning 'excessive (sometimes simply eccentric) use of the '-r-' sound. This word was more current in the nineteenth century than presently, and you are advised not to use it for fear of confusion with rhoticism, or rhoticity, 'the quality of being [or producing] rhotic pronunciations'.

OED defines rhotic as "Of or pertaining to a variety or dialect of English in which r is pronounced not only in pre-vocalic position but also before a consonant or word-finally; characterized by r-pronouncing".

Etymological note: The word rhotic is derived from the name of the seventeenth letter of the Greek alphabet, ρ (upper case Ρ), representing a similar sound to that of the English (Roman alphabet) r, R. At the start of a word, this is usually written with a 'rough breathing', ῤ Ῥ: equivalent to inserting an '-h-' after the '-r-'. This is a stronger 'r' sound than is usual in educated British English speech.