a. [ L. argillaceus, fr. argilla. ] Of the nature of clay; consisting of, or containing, argil or clay; clayey. [ 1913 Webster ]
Argillaceous sandstone (Geol.),
Argillaceous iron ore,
Argillaceous schist or
state
a. consisting of, or containing, calcareous and argillaceous earths. [ 1913 Webster ]