Definition of elvan in US English:

elvan

noun

Geology
  • Hard intrusive igneous rock found in Cornwall, England, typically quartz porphyry.

    • ‘Molybdenite and corundum are also found in the schist through which the elvan dykes have cut.’
    • ‘Less frequently elvan has been met with in apparently isolated masses.’

Origin

Early 18th century: perhaps via Cornish from Welsh elfen ‘element’.

Pronunciation

elvan

/ˈelvən/