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Webster 1913 Edition

Noun.

[Perh. fr.

clinch

to make fast]

(Mining)

Indurated clay. See

Noun.

, 3.

One of the hard beds of the lower chalk.

Dana.

Noun.

Among miners, indurated clay, found in coal pits next to the coal.

clunch ‎(countable and uncountable, plural clunches)

(Britain) A traditional building material mostly made of chalk or clay.
- 1736, Charles Parkin, History of Norfolk, volume 6
  The manor-house stands near the church, and is a large convenient old house built of clunch, stone, &c. with good gardens and walks adjoining to the river side.