D defs.my
Entry 1 sense Webster, 1913

petrograph

/(pĕt"rō̇*grăf`)/ · pet·ro·graph · IPA
01 n. A carving or drawing on rock, especially one made by prehistoric humans; called also a petrograph.
  1. 1.
    A carving or drawing on rock, especially one made by prehistoric humans; called also a petrograph. Also: petrograph