TONGUE-TWISTER. A sentence, phrase, or rhyme that is difficult to pronounce, especially when said quickly. The difficulty is usually caused by ALLITERATION: the presence of similar-sounding consonants interspersed with a variety of vowels, as in Peter Piper picked a peck of pickled pepper. Such tongue-twisters may be accidental or deliberately used for especially comic effect. They became particularly popular in the 19c as rhymes designed to cause pronunciation problems and elocutionists used examples like Truly rural and She sells sea-shells on the sea-shore to improve enunciation.

tongue-twist·er • n. a sequence of words or sounds, typically of an alliterative kind, that are difficult to pronounce quickly and correctly, as, for example, tie twine to three tree twigs.DERIVATIVES: tongue-twist·ing adj.