- a nonporous, dark-colored sandstone containing angular particles of other rocks
- a fine-grained conglomerate resembling sandstone
Origin of graywackeAnglicization of German grauwacke: see gray; eastern; English wacke, a rock like sandstone from German
Any of various dark gray sandstones that contain shale.
Origin of graywackePartial translation of German Grauwacke grau gray Wacke rock ( from Middle High German) ( from Old High German waggo boulder ; see wegh- in Indo-European roots.)
(countable and uncountable, plural graywackes)
- Alternative form of greywacke.