What does marl mean?
Marl is a soft, calcium-carbonate-rich clay that occurs in soils and in layers formed from ancient marine mud. In agriculture, marl can improve acidic ground and provide valuable lime, while its plasticity has also made it useful in pottery and brickmaking. Geologists use the word for particular sedimentary beds, including deposits that may contain fossils. The noun is usually treated as a mass noun, though marls can refer to separate formations. An older verbal use of marl means to cover something with marl or to disguise it, but that sense is now largely archaic or regional. The word is especially useful to readers interested in geology, soil science, ceramics, or regional history because it identifies a material more specific than ordinary clay: one whose pale colour and lime content often reflect its origin in carbonate-rich marine sediment.
A soft, pale clay containing calcium carbonate, occurring in certain soils and geological deposits; it may also be used in pottery, brickmaking, or as a soil amendment.
"The farm was built on fertile marl that was rich in lime."
Usually an uncountable noun; marls is used occasionally for distinct sedimentary beds.
To cover something with marl; archaically, to disguise or conceal something.
"The criminals tried to marl the stolen documents by altering their appearance."
This verb is now chiefly archaic or regional and is rarely used in modern standard English.
Usually marl is uncountable; the plural marls is used mainly for distinct geological beds or deposits.
"The cliffs expose alternating marls laid down in an ancient shallow sea."
Marl can be both a fertile soil ingredient and a time capsule: some marl beds preserve the fossils of creatures that lived in ancient seas.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does marl come from?
The word entered Middle English from Old French marle, denoting a kind of clay, and is usually traced through Medieval Latin to a term related to Latin margo, meaning an edge or boundary. That same Latin root also underlies words such as margin and marginal, although their modern senses developed through a separate line of usage. The verbal sense arose by extension from the material marl itself.
Related word forms
How marl is actually used
As a noun, marl is usually an uncountable mass noun, although geologists may use the plural marls for distinct deposits or beds. The verb is uncommon and usually encountered in archaic, historical, or regional writing.