Definition of argillaceous in English:

argillaceous

adjective

Geology
  • (of rocks or sediment) consisting of or containing clay.

    • ‘It is predominantly found in the marl areas but also, more rarely, in fine-grained argillaceous limestones.’
    • ‘These specimens were mostly weathered out from dark gray, argillaceous limestones.’
    • ‘In the footwall, there is density increase and porosity reduction of the argillaceous matrix approaching the fault.’
    • ‘They were found as scattered individuals in the argillaceous limestones.’
    • ‘The 284 m section is composed of calcareous shales, argillaceous limestone, and limestone.’

Origin

Late 17th century: from Latin argillaceus (from argilla clay) + -ous.

Pronunciation:

argillaceous

/ˌɑːdʒɪˈleɪʃəs/