Definition of elvan in English:

elvan

noun

Geology
  • [mass noun] Hard intrusive igneous rock found in Cornwall, 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

/ˈɛlv(ə)n/