Definition of Rupelian in US English:

Rupelian

adjective

Geology
  • Designating the lower (older) stage of the Oligocene series, exemplified by certain clays and shales in Belgium and Germany; of or relating to this stage.

noun

Geology
  • The Rupelian stage; the strata collectively dating from this time.

Origin

Mid 19th century. From French Rupelien from Rupel, the name of a small tributary of the river Scheldt in Belgium + -ien.

Pronunciation

Rupelian

/rʊˈpiːlɪən/