chain shift noun1 •A phonological modification of a vowel system or sometimes consonant system in which a change in a particular vowel or consonant causes other adjacent vowels or consonants to also change in order to avoid phonemic mergers.Many non-Antipodeans cannot readily distinguish Australian and New Zealand English, because the phonologies basically overlap with the exception of an upwards chain shift in the front vowels. — 2019 formschain shifts
