Noun
mudrock (countable and uncountable, plural mudrocks)
(geology) Any of various fine-grained siliciclastic sedimentary rocks.
Most authors use " shale " as a term for a fissile mudrock (regardless of grain size) although some older literature uses the term "shale" as a synonym for mudrock. Source: Internet
Jason Mudrock, leader of the SWAT team, uses tactics and an armored vehicle to protect lives. Source: Internet