Definition of rudaceous in English:

rudaceous

adjective

Geology
  • (of rock) composed of relatively large fragments (larger than sand grains)

    • ‘In central Telemark, the Bandak Group comprises voluminous elastic and rudaceous sediments, basaltic lava flows and minor felsic volcanics.’
    • ‘Composed of angular rather than rounded fragments, this type of rudaceous sedimentary rock occurs in volcanic vents where sides of the vent or pipe are broken by explosions.’

Origin

Early 20th century: from Latin rudus rubble + -aceous.

Pronunciation:

rudaceous

/ro͞oˈdāSHəs/