mestome
/ˈmɛstəʊm/(also mestom) Botany
noun
The conducting elements and associated parenchyma of a vascular bundle (as opposed to the strengthening mechanical elements). Now historical.
Origin
Late 19th century; earliest use found in George Goodale (1839–1923). From German Mestom from ancient Greek μέστωμα from μεστοῦν to fill up (from μεστός full, of unknown origin) + -ωμα.