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milk of magnesia

noun
  1. a milky white suspension in water of magnesium hydroxide, Mg (OH)2, used as an antacid or laxative.

Origin of milk of magnesia

First recorded in 1875–80; formerly trademark
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for milk of magnesia

milk of magnesia

noun
  1. a suspension of magnesium hydroxide in water, used as an antacid and laxative
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
Word Origin and History for milk of magnesia
n.

1880, proprietary name for white suspension of magnesium hydroxide in water, taken as an antacid, invented by U.S. chemist Charles Henry Phillips. Herbal or culinary preparations resembling milk had been similarly named (e.g. milk of almond) since early 15c.

Online Etymology Dictionary, © 2010 Douglas Harper
milk of magnesia in Medicine

milk of magnesia

n.
  1. A milky white aqueous suspension of magnesium hydroxide used as an antacid and a laxative.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.