[1] : The Collaborative International Dictionary of English v.0.48

argillaceous \ar`gilla"ceous\, a. l. argillaceus, fr.
   argilla.
   of the nature of clay; consisting of, or containing, argil or
   clay; clayey.
   1913 webster

   argillaceous sandstone geol., a sandstone containing much
      clay.

   argillaceous iron ore, the clay ironstone.

   argillaceous schist or state. see argillite.
      1913 webster
see also:
argillaceous sandstone argillaceous iron ore argillaceous schist state argillite 

[2] : WordNet (r) 2.0

argillaceous
     adj : resembling or containing clay; "argillaceous rocks" syn: clayey
           ant: arenaceous
see also:
clayey arenaceous 

Argillaceous >> A Words
Argillaceous, definition of term: Argillaceous
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