• synonyms


noun Chemistry.
  1. Also called acid phosphate. a mixture of calcium acid phosphate and calcium sulfate prepared by treating phosphate rock with sulfuric acid: used chiefly as a fertilizer.
  2. Also called triple superphosphate. a mixture prepared with phosphoric acid and containing about 45 percent of soluble phosphates, used as a fertilizer.
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Origin of superphosphate

First recorded in 1790–1800; super- + phosphate
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for superphosphate

Historical Examples

  • It has also been used for mixing with superphosphate of lime.

    Manures and the principles of manuring

    Charles Morton Aikman

  • Impure chloride of magnesium mixed with superphosphate of lime.

  • There are even drills for dropping water combined with superphosphate.

    Knowledge is Power:

    Charles Knight

  • Finally they are watered with water containing molasses and superphosphate of lime, as recommended by Corenwinder.

  • Good results will also follow an application of bone meal or superphosphate at the rate of from 300 to 500 pounds per acre.

British Dictionary definitions for superphosphate


  1. a mixture of the diacid calcium salt of orthophosphoric acid Ca(H 2 PO 4) 2 with calcium sulphate and small quantities of other phosphates: used as a fertilizer
  2. a salt of phosphoric acid formed by incompletely replacing its acidic hydrogen atoms; acid phosphate; hydrogen phosphate
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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