fuller's earth

 

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fuller's earth

Wikipedia

• IPA^(key): /ˌfʊləz ˈɜːθ/

fuller's earth (uncountable)

1. A fine clay used in fulling cloth.

   Synonym: walker's earth (rare)

   • 1785 October 17, The Times, page 3 col. D:

     On Lord Sunderland's estate, in the county of Westmeath, there is a fine strata of fuller’s earth, a commodity of which our woollen manufacturers stand much in need: yet this bed lies unnoticed to all, except the peasantry on the soil.

   • 1892, Arthur Conan Doyle, The Adventure of the Engineer's Thumb‎^[1]:

     You are probably aware that fuller’s earth is a valuable product, and that it is only found in one or two places in England?