The story
From the cran- of cranberry as an archetype. Cran- is from Low German Kraan (“crane”), but is now a bound morpheme, hence an example of a cranberry morpheme.
Etymology from Wiktionary, CC BY-SA 4.0.
cranberry morpheme
Today it means: A bound morpheme within a complex word that is a fossil and whose meaning is opaque to the present speakers of the language. Full definition →