dissimilation (n.)

A general term in PHONETICS and PHONOLOGY to refer to the influence exercised by one sound SEGMENT upon the ARTICULATION of another, so that the sounds become less alike, or different. Such changes have mainly been noticed in HISTORICAL LINGUISTIC studies, where the effects have manifested themselves over a long period of time (e.g. pilgrim from Latin peregrinus, with the first r ‘dissimilating’ to l), but SYNCHRONIC dissimilations are also possible, as when we avoid a sequence of identical sounds (cf. the difficulty of tongue-twisters such as Will will willingly . . . ). As with the opposite effect, ASSIMILATION, it is possible to classify dissimilations into types, based on the place, degree and direction of the changes involved.