In
phonology,
syncope (; Greek:
syn- +
koptein "to strike, cut off") is the loss of one or more sounds from the interior of a word, especially the loss of an unstressed vowel. It is found both in
synchronic analysis of languages and
diachronics. Its opposite, whereby sounds are added, is
epenthesis. A syncope rule has been identified in Tonkawa, an extinct American Indian language, whereby the second vowel of a word deletes if it is not adjacent to a consonant cluster or final consonant.