Webster’s Revised Unabridged Dictionary · 1913
Purbeck beds
Pur′beck beds′ (pûr′bĕk bĕdz′). [So called from the Isle of Purbeck in England.] (Geol.) The strata of the Purbeck stone, or Purbeck limestone, belonging to the Oölitic group. See the Chart of Geology.