(usu in passive) in linguistics, to alter (a consonant sound) so that it diverges from a similar one in proximity to it
‘Glamour’ is a doublet of ‘grammar’, with ‘r’ dissimilated to ‘l’
said of consonant sounds: to become dissimilar in this way
dissimilation /-ʹlaysh(ə)n/ noun
dissimilatory /-ət(ə)ri/ adj
[dis- + Latin similis same, modelled on assimilate]