rhotacism

noun

rho·​ta·​cism ˈrō-tə-ˌsiz-əm 

1

: a defective pronunciation of r

especially : substitution of some other sound for that of r

2

linguistics : the historical change of a voiced consonant sound (such as the alveolar consonants \z\, \d\, \l\ or \n\) to an r-like consonant

Word History

Etymology

borrowed from German Rhotacismus, from Middle Greek rhōtakízein "to use the letter ρ or the sound r excessively or incorrectly" + German -ismus -ism — more at rhotacize

First Known Use

1830, in the meaning defined at sense 2

Medical Definition

rhotacism

noun

rho·​ta·​cism ˈrōt-ə-ˌsiz-əm 

: a defective pronunciation of r

especially : substitution of some other sound for that of r