| Definition -
(Aka unique morpheme)
A morpheme that has no currently used meaning or grammatical function but which still serves to distinguish one word from another, e.g. the cran- in cranberry and the mul in mulberry.
1. They occur for several reasons. For example:
(a) a dialectal word can become part of a standard language compound, but not have independant meaning in the language e.g. the skite in blatherskite means "contemptible person" in Scots but has no meaning apart from this case in English.
(b) A word's root form can become obsolete but can remain in the language as part of a compound, e.g. the Middle English luke (tepid) in lukewarm.