rhotacize

rhotac(ism) + -ize, or borrowed from Middle Greek rhōtakízein "to use the letter ρ or the sound r excessively or incorrectly," derivative of rhô "the letter ρ," after *iōtakízein, presupposed by iōtakismós "excessive use of the letter ι," derivative, with -izein -ize, of iôta iota (with -k- of uncertain origin)