A diaphoneme is an abstract phonological unit that identifies a correspondence between related sounds of two or more varieties of a language or language cluster. For example, some English varieties contrast the vowel of "late" () with that of "wait" or "eight" (). Other English varieties contrast the vowel of "late" or "wait" () with that of "eight" (). This non-overlapping pair of phonemes from two different varieties can be reconciled by positing three different diaphonemes: A first diaphoneme for words like "late" (), a second diaphoneme for words like "wait" (), and a third diaphoneme for words like "eight" ().