[ muhd-stohn ]
/ ˈmʌdˌstoʊn /

noun Geology.

a clayey rock with the texture and composition of shale but little or no lamination.

Origin of mudstone

First recorded in 1730–40; mud + stone Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for mudstone


/ (ˈmʌdˌstəʊn) /


a dark grey clay rock similar to shale but with the lamination less well developed
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for mudstone


[ mŭdstōn′ ]

A fine-grained, dark gray sedimentary rock consisting primarily of compacted and hardened silt and clay, similar to shale but without laminations. The proportions of silt and clay in mudstone are approximately equal.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.