"Tongue twisters" are a type of phrase or sentence that is difficult to say quickly and accurately because it has repetitive or challenging sounds or syllables. Full definition
The initials IBCLC can be a bit of tongue twister! (cindyandjana.com)
The Terrible Tongue Twister segment (AKA «Twisting by the Fool») is sponsored by Findaway Voices, who provide all the tools that an independent author or small publisher needs in order to get into the digital audiobook market. (starkreflections.ca)
, a silly collection of Seussian tongue twisters for the whole family. (prweb.com)